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Letsfit IW1 Smartwatch Manual

Letsfit IW1 Smartwatch Manual Image

Letsfit IW1 Smartwatch

Letsfit IW1 Smartwatch

Thank you for purchasing our products. This manual addresses the safety guidelines, warranty, and operating instructions. Please review this manual thoroughly before operating your device.

All pictures in this manual are for illustration purpose only. Actual product may vary due to product firmware upgrade and app upgrade.

Getting Started

What’s in the Box

What’s in this Document

This manual gets you started quickly with setting up your watch. Setup ensures that your watch can synchronize its data with the Letsfit app, where you can get detailed information on your stats, view historical trends, log sleep, and more. As soon as setup is complete, you’re ready to start moving. The remainder of the manual walks you through every function on your IW1.

Setting up Your Watch

Charging Your Watch

Please fully charge your watch before initial use.

  1. Insert the USB plug of the charging cable into the USB port on your computer or a UL-certified USB wall charger.
  2. Hold the other end of the charging cable near the port on the back of the watch until it attaches magnetically.
  3. Make sure the pins on the charging cable lock securely with the port. The connection is secure when the watch vibrates and the battery icon with percent charged appears on the screen.

    When the watch shows that the battery is low, connect the watch to a USB port with 5V-500mA.
    While the watch charges, there is a battery progress circle on the screen and you can check the battery level at any time.
  4. Remove the watch from the power supply once fully charged.
  • USB charger requirement: DC USB port (5V-500mA)
  • Charging time: Approximately 2 hours

Disassembling / Assembling Your Watch


  1. To remove the wristbands, turn over the watch and find the quick-release lever.
  2. While pressing the quick-release lever inward, gently pull the wristband away from the watch to release it.

  3. Repeat on the other side.


  1. To reattach the wristbands, slide the pin (the side opposite the quick-release lever) into the notch on the watch. Attach the wristband with the clasp to the top of the watch.
  2. While pressing the quick-release lever inward, slide the other end of the wristband into place.
  3. When both ends of the pin are inserted, release the quick-release lever.

Wearing Your Watch

All-day Wear and Exercise

For all-day wear when you’re not exercising, wear the device on your wrist horizontally, a finger’s width below your wrist bone and lying flat, the same way you would put on a watch.

For optimized heart rate tracking, keep these tips in mind:

  1. Experiment with wearing the watch higher on your wrist during exercise. Because the blood flow in your arm increases the farther up you go, moving the watch up a couple of inches can improve the heart rate signal. Also, many exercises such as bike riding or weight lifting require you to bend your wrist frequently, which is more likely to interfere with the heart rate signal if the watch is lower on your wrist.
  2. Do not wear your watch too tight. A tight band restricts blood flow, potentially affecting the heart rate signal. This being said, the watch should also be slightly tighter (snug but not constricting) during exercise than during all-day wear.

Using Your Watch

App Installation

Use the watch with our customized Letsfit app. You can download Letsfit  from App Store / Google Play or scan the QR codes below to download.

Note: The Letsfit app is only compatible with smartphones, not tablets or PCs.

Smart Phone System Requirements

  • iOS 11.0 & higher
  • Android 6.0 & higher
  • Bluetooth 4.0 & higher

Account Registration and Login

Please register an account with a valid email address. After registration, check your email box to complete email verification, and then tap “Verified” to log in.

Pairing the Watch with Your Phone

Please pair the watch with your phone in the Letsfit app, NOT in the Bluetooth settings of your phone.

  1. Enable the Bluetooth of your smartphone.
  2. Open the Letsfit app on your smartphone and go to the “Settings” page, tap “+ Pair new device”.
  3. Tap “IW1”, and your smartphone starts scanning.
  4. Select the watch language on the watch and enter the QR code interface as instructed.
  5. Use the Letsfit app to scan the QR code displayed on your watch to connect the watch to your smartphone.


  • You can also search this device in the app to pair (Go to “Settings” page “+ Pair new device” “IW1” tap “Search Devices”).
  • Once the watch is connected to your app, the watch will automatically search and reconnect itself if the connection is lost or when Bluetooth is restarted after manual disconnection.
  • If you unpair the watch with the app, the information on the watch will be reset and the watch will be restarted. Please do not unpair the watch with the app unless there is an issue that will require a reset.
  • The watch can only pair with one smartphone at a time. When pairing, please ensure the watch and your smartphone is within 0.5 meters distance.

App Interfaces

When you start a sport mode on your watch, detailed data and graphs will be displayed here after the exercise is over (swipe down to sync data first).

Tap “IW1”, you can customize call / message / alarm alert or set other parameters.

Getting to Know Your Watch

Basic Operation

  • Turn on / off the watch:
    Press and hold the function button for 3 seconds.
  • Wake a dimmed screen:
    Press the function button or turn your wrist towards you.
  • Return to the previous interface:
    Press the function button or swipe the screen to the right.

Watch Interfaces

This is a touch screen; swipe the screen to go to different interfaces, and tap to enter the function.

The home screen is a clock. On the clock:

  • Swipe up to see the quick settings bar (do not disturb, wrist sense, night mode, settings).
  • Swipe down to see notifications.
  • Swipe left to the function list, including workout, today, heart rate, blood oxygen, breath, timer, stopwatch, alarm, music control, and settings.
  • Swipe right to view today’s daily activity data (You can customize this interface in the Letsfit app. Go to the “Setting” page “IW1” “Control Center”.)

After the watch is paired with your phone, the home screen will display the time and date.

You can customize the home screen by following the steps below:

  1. Go to “Settings” “General” “Watch Face” on the watch.
  2. Swipe the screen to choose a watch face and tap to confirm.
  1. Open the Letsfit app, go to the “Settings” page “IW1” “Watch Faces”. Select a watch face and then choose the information you want to display on the home screen.
  2. Tap “Confirm” to finish setting

Function Introduction

Tracks your exercise data in up to 14 sports modes. Choose the mode that you want to start on the watch.

Check your daily activities and sleep data.

Tracks your real-time heart rate automatically and continuously.

 Measures your 2 blood oxygen level.

Guides your breathing for a relaxation.

Customize your timer.

 Use the stopwatch to make your exercise more standardized.

Control the music playing of your smartphone.

Set different types of alarms in the app to make the watch vibrate to remind you.

Some basic settings and information of the watch.

Tracking Sports

The watch tracks your exercise data in up to 14 sports modes.

Start a sport
Tap “Workout” Swipe the screen to select a sports mode you want to start.

GPS connecting (Only for Outdoor Run / Outdoor Cycle / Outdoor Walk modes)

When you start an outdoor sport, the watch begins searching GPS signal. Please let the Letsfit app run in the background and allow the location services on your phone, then move to an open area and stand still to better receive the signal. After the GPS is connected, tap ” ” to start the exercise.

When the GPS signal is weak, you can start Outdoor Run, Outdoor Cycle, Outdoor Walk in non-GPS mode. Your movement route will not be displayed in your training record after the exercise is ended.

During sports
Swipe the screen up or down to flip through exercise data. Swipe the screen to the left so you can control the music playing on your phone.

End the sport
Press the function button and tap ” ” to end the sport.

Exercise data is displayed after the exercise has ended. Swipe up the screen to flip through exercise data:


  • After ending an exercise, you can view detailed data and graphs in the app (Go to the “Training” page, swipe down the page to synchronize data, and tap the exercise you just ended).
  • After you finish the outdoor cycling, outdoor running or outdoor walking exercise in GPS mode, your movement track will be displayed in the app (Go to the “Training” page of the app, and then tap on the exercise you just ended to view).
  • Data of exercises less than 2 minutes will not be saved.
    When the battery level is less than 10%, the watch enters low battery mode, in which you cannot start a sports mode. Please charge the watch to operate it again.

Tracking Daily Activity Data

The watch tracks your all-day activity data, including steps, distance, calories burned, sleep, and workout data.

Monitoring Heart Rate

After entering the heart rate interface, the watch tracks your real-time heart rate automatically and continuously. You can view your detailed heart rate data on the watch screen or in the app.

Note: To monitor heart rate more accurately, wear the watch on the upper position of your wrist and a bit tighter than usual when you exercise. In addition, complete your profile in the app.

Measuring Blood Oxygen Level

Before measuring, wear the watch a finger-width below the wrist bone and a bit tighter than usual.

  1. Tap “Blood Oxygen” to enter the blood oxygen level detection mode.
  2. When measuring, keep your arm flush with your chest and the watch screen facing up. Keep your arm still to ensure the accuracy of the data.

Sleep Detection Mode:
If you want the watch to track your blood oxygen level during sleep, please open the Letsfit app, go to the “Settings” page “IW1”, and turn on the blood oxygen measurement switch. The blood oxygen data will then be displayed in the app (Go to the “Activity” page “Sleep Schedule”).

Breathing Guide

Swipe the screen of the watch to enter breathing mode. Select the duration of the breathing training and follow the instructions to breathe. If you want to end the breathing training, press the function button, or swipe the screen to the right.

Setting Alarms

  1. Go to the “Settings” page in the Letsfit app and tap “IW1”.
  2. Tap “Alarm” to enter the alarm setting interface.
  3. Tap “Add” to add an alarm.
  4. Set the alarm time, name, vibration period and repeat time.
  5. Tap “Confirm” to save your settings.
    You can enable / disable the alarm on your 07:00 am watch (Tap “Alarm” on the watch and turn Everyday on/off the alarm you set.)

Controlling Phone Music

After the watch is connected to the Letsfit app on your phone, tap “Music Control” on the watch to enter the function and control the music playing on your phone.

You can only control the music player that’s running on your phone.

More Functions

Call Notification
When there is an incoming call, the watch vibrates to alert you, and the screen displays the caller ID.
Tap ” ” on the watch screen to reject the call.
Tap ” ” to turn on vibration-free mode.


  • Only when “Notification alerts” is enabled in the app (“Settings” page “IW1” “Notification alerts”), will calls be notified.
  • When the “Do not disturb” function is enabled in the app (“Settings” page “IW1” “Do Not Disturb”) or on the watch (Quick settings bar  ), calls will not be notified on the watch during the do-not-disturb period.

Message Notification
When messages (like Facebook, Twitter, and Instagram messages) come in, the watch vibrates to alert you, and the screen displays the message content.


  • Only when “Notification alerts” is enabled in the app (“Settings” page “IW1” “Notification alerts”), will messages be notified.
  • When the “Do not disturb” function is enabled in the app (“Settings” page “IW1” “Do Not Disturb”) or on the watch (Quick settings bar  ), messages will not be notified on the watch during the do-not-disturb period.

Sedentary Reminder
The watch vibrates to remind you to get up and move around when you have been sitting too long (Go to “Activity” page “Active Hours” “Sedentary Alert Settings” enable the movement reminders function and set the remind interval.)

1) Tap “Stopwatch” to enter the function.
2) Tap ” ” to start.

1) Tap “Timer” to enter the function.
2) Choose the countdown time or customize your timer.

Basic Specifications

  • Model No.: IW1
  • Sync: Bluetooth 5.0
  • Screen: 1.4″ TFT LCD
  • Battery Capacity: 250mAh
  • Working Voltage: 5V-500mA
  • Working Temperature: -10C to 40C
  • Weight: 1.2oz (34g)
  • Waterproof Rating: IP68
  • Working Time: 5-7 days


◉Failure to re-pair the watch with the Letsfit app on your smartphone

  1. Swipe the screen of watch to enter settings mode. Tap “System” and choose “Reset”. The information on the watch will be reset and the watch will be restarted.
  2. Select the watch language on the watch and enter the QR code interface as instructed.
  3. Use the Letsfit app to scan the QR code displayed on your watch to pair.

If you still fails to connect the watch to the app, please kindly take the following steps:

  1. Make sure your smartphone’s Bluetooth is enabled and make sure the watch is not connected to other smartphones.
  2. Search this device in the app to pair (Go to the “Settings” page “+ Pair new device” “IW1” tap “Search Devices”).
  3. Make sure the distance between your smartphone and the watch does not exceed 0.5 meters and keep the watch screen always on when pairing.

◉ Occasional failure to connect with Bluetooth

Reboot your smartphone or restart your smartphone’s Bluetooth.

◉ Failure to receive SMS / calls notifications

Calls / SMS notification function works when the watch connects to your smartphone via the app. Please kindly refer to the following tips:

  1. Go to your smartphone Settings, find Letsfit app, enable the Location and all Notifications.
  2. Enable your phone’s Bluetooth and go to the Letsfit app to pair the watch.
  3. Open the app. Go to the “Settings” page “IW1” “Notification alerts”, turn on “Notification alerts”.
  4. Make sure the “Do not disturb” function is not enabled in the app or the watch.

◉ The watch is disconnected from the Letsfit app on your smartphone

The watch will disconnect from your smartphone in the following cases:

  1. Smartphone Bluetooth is off or exceeds the Bluetooth connection range (the maximum Bluetooth connection range is 10 meters and can easily be reduced by walls, furniture, etc.)
  2. The Letsfit app is closed on the phone. (This can occur automatically under certain circumstances.)

To reconnect the watch to your smartphone, please kindly take the following steps:

  1. Go to your smartphone system Settings, find the Letsfit app, and enable the Location and Bluetooth.
  2. Clear all running / background processes on your smartphone. Open the Letsfit app, go to the “Settings” page, tap “IW1”, and then the watch will reconnect to your smartphone and update data. You can also restart your smartphone and Bluetooth, then re-pair the watch in the app.

Blood Oxygen Level Measurement Accuracy

The Blood oxygen level will be affected by factors such as motion, watch placement on the wrist, skin temperature and skin perfusion. These factors will cause fluctuations in blood oxygen measurements.

For a single measurement on the watch, please wear the watch a finger-width below the wrist bone, snug but comfortable on your wrist. When measuring, stay still and make sure your wrist is flat with the watch facing up. If you are sitting, you can rest your arm on a table with the watch facing up. For sleep blood oxygen detection, please wear the watch snugly but comfortable on the wrist when sleeping.

The smart watch blood oxygen sensor isn’t a medical device and won’t be able to diagnose or monitor any medical conditions. If there is a problem with the measurement, we recommend you consult your doctor.


We strive to build our products with the highest attention to detail and craftsmanship. However, sometimes there are occurrences of a defect, so we are happy to offer a ONE-year hassle-free warranty on all our devices as we continue to make amazing products. Please contact us if you have any questions about our devices.

Important Safety Instructions

The device contains electrical equipment that may cause injury if not used properly. For example, prolonged contact may contribute to skin allergies for some users. To reduce irritation, please read the safety guidelines on the following pages to ensure proper use and care.

  • Do not expose your device to liquid, moisture, humidity or rain while charging; do not charge your device when it is wet, as this may result in electrical shock and injury.
  • Keep your device clean and dry. Do not use abrasive cleaners to clean your device.
  • Consult your doctor before use if you have any preexisting conditions that might be affected by using this device.
  • Do not wear it too tight. If your device feels hot or warm, or if it causes any skin irritation or other discomforts, please discontinue using your device and consult your doctor.
  • Do not expose your watch to extremely high or low temperatures.
  • Do not leave your watch near open flames such as cooking stoves, candles, or fireplaces.
  • This product is NOT a toy ­ never allow children or pets to play with this product. Always store the product out of the reach of children. The devices themselves or the many small parts they contain may cause choking if ingested.
  • Never try to abuse, crush, open, repair or disassemble this device. Doing so will void the warranty and can result in a safety hazard.
  • If any parts of your product require replacement for any reason, including normal wear and tear or breakage, please contact us.
  • Do not use your device in a sauna or steam room.
  • Dispose of this device, the device’s battery and its package in accordance with local regulations.
  • Do not check any notifications, GPS, or any information on your device’s display while driving or in other situations where distractions could cause injury or hazard. Always be aware of your surroundings while exercising.

Battery Warnings

A lithium-ion battery is used in this device. If these guidelines are not followed, batteries may experience a shortened life span or may cause fire, chemical burn, electrolyte leakage, and/or injury.

  • Do not disassemble, modify, remanufacture, puncture or damage the device or batteries.
  • Do not remove or attempt to remove the non-user-replaceable battery.
  • Do not expose the device or batteries to fire, explosion, or other hazards.

Health Warnings

  • If you have a pacemaker or other internal electronic device, consult your physician before using a heart rate monitor.
  • The optical wrist heart rate monitor emits green light and flashes occasionally. Consult your physician if you have epilepsy or are sensitive to flashing lights.
  • Always consult your physician before beginning or modifying any exercise program.
  • The device, accessories, heart rate monitor, blood oxygen level measurement and related data are intended to be used only for general fitness and wellness purposes, not for medical purposes, and are not intended to diagnose, monitor, treat, cure, or prevent any disease or condition.
  • The heart rate and blood oxygen level readings are for reference only, and no responsibility is assumed for the consequences of any false readings.
  • While the optical wrist heart rate monitor technology typically provides the best estimate of a user’s heart rate, there are inherent limitations with the technology that may cause some of the heart rate readings to be inaccurate under certain circumstances, including the user’s physical characteristics, fit of the device, and type and intensity of activity.
  • The smart watch relies on sensors that track your movements and other metrics. The data and information provided by these devices are intended to be a close estimation of your activity and metrics tracked, but may not be completely accurate, including step, sleep, distance, heart rate, and calorie data and blood oxygen levels.
  • If you have eczema, allergies or asthma, you may be more likely to experience skin irritation or allergies from a wearable device.
  • Whether you have the conditions above or not, if you start to experience any discomfort or skin irritation on your wrist, remove your device. If symptoms persist longer than 2-3 days of not using your device, contact your doctor.
  • If you sweat for more than two hours while wearing your watch, be sure to clean and dry your band and your wrist to avoid skin irritation.
  • Prolonged rubbing and pressure may irritate the skin, so give your wrist a break by removing the band for an hour after extended wear.


  • Regularly clean your wrist and the smart watch, especially after sweating during exercise or being exposed to substances such as soap or detergent which may adhere to the internal side of the watch.
  • Do not wash the watch with household cleanser. Please use soapless detergent, rinse thoroughly and wipe with a soft towel or napkin.
    While the watch is water resistant, wearing a wet band is not good for your skin.
  • If your bands get wet–for example after sweating or showering–clean and dry them thoroughly before putting them back on your wrist.
  • Be sure your skin is dry before you put your bands back on.
  • Do not bring your device into contact with any sharp objects, as this could cause scratches and other damage.
  • For light-colored arm bands, minimize direct contact with dark-colored clothing, as color transfer can occur.


What are the supported languages?

English, Simplified Chinese, Traditional Chinese, Korean, Spanish, French, German, Italian and Japanese.

What is the warranty period?

One year from the date of purchase.

Can you answer calls on Letsfit smart watch?

The device has a speaker and microphone that allow you to answer calls made to your smartphone.

How do you charge a Letsfit?

insert the built-in USB plug into a USB port for charging.

Does Letsfit measure blood pressure?

Letsfit EW1 Smartwatch with Blood Pressure Monitor | Free Shipping – Wellbots.

Is Letsfit IW1 waterproof?

IP68 waterproof grade means the IW1 protects against sweat, rain, water splashes and submergence.

Is there a Letsfit app?

Wide Compatibility: Our smart watch is compatible with our very own Letsfit app, and works with Android OS 6.0/iOS 11.0 or above and Bluetooth 4.0 or later (Suitable for smartphones only).

How do I set the time and date on my smartwatch?

Set your watch’s time and date
If the screen is dim, tap it to wake up the watch.
Swipe down from the top of the screen.
Tap Settings . If you don’t find it straight away, swipe left.
Tap System Date and time. Choose your time settings.

What is the charging time?

The charging time is about 1.5 hours.

How do I know when my watch needs to be charged?

When your watch shows that it needs to be charged, attach it to a charging cable and connect it to a computer or a UL-certified USB wall charger. The watch will charge automatically once connected to a power source.

Is there any way I can check if my watch is charging?

Yes, you can check if your watch is charging by looking at its screen. If you see a battery icon with a percent charged, then your watch is charging. If you don’t see any battery icon, then your watch isn’t connected to a power source or isn’t attached properly to a charging cable. Please make sure that your watch is connected properly and try again. If this doesn’t work, please contact us at [email protected] . We’ll be happy to help you!

How do I turn on my watch?

Press and hold down for about 2 seconds until its screen lights up, then release . You’ll see a battery icon with percent charged if your watch has been fully charged or an empty battery icon if it hasn’t been fully charged yet . If you don’t see either of these icons, please contact us at [email protected]. We’ll be happy to help!

How do I turn off my watch?

Press and hold down for about 2 seconds until its screen lights up, then release . You’ll see an empty battery icon if it hasn’t been fully charged yet or an empty battery icon with percent charged if it has been fully charged already . If you don’t see either of these icons, please contact us at [email protected]. We’ll be happy to help! Setting up Your Watch Watch Setup lets you connect your IW1 with Letsfit app via Bluetooth so that all data collected by Letsfit app can be synchronized with Letsfit app automatically.

Letsfit IW1 Smartwatch

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