Key features:

Cardio fitness score
Built-in GPS
Heart rate variability
Alexa built in
Stress management score
Smart notifications

Fitbit ECG (Electrocardiogram) App

Compatible ECG app lets you assess your heart rhythm for atrial fibrillation—a heart rhythm irregularity—and share results with your doctor.

Stress management score

See how well your body's handling stress each day. Detailed score breakdown available with Premium

Heart rate variability

Tracks HRV–your time between heartbeats. A downward trend over multiple nights could potentially be a result of overtraining, lack of sleep, stress and more.

Relax breathing sessions

Do simple guided breathing sessions by following prompts on your wrist.

Active zone minutes

Tracks your time in heart rate zones so you get credit when you work harder. Workouts in cardio or peak zones earn double minutes.

Exercise modes

Track your favourite exercises like runs, bike rides, weights, yoga & more and get live stats on your wrist.

Vibrant colour display

Bring your stats to life on a new colour touchscreen that’s two times brighter than Charge 4 in daylight and protected by Corning® Gorilla® Glass 3.

Up to 6-day battery life

Track all your moves for up to 6 days without having to stop for a charge with a long battery life

Specifications:

Size

Small – fits wrists 129 – 175mm in circumference

Large – fits wrists 158mm – 209mm in circumference

Sensors & Components

Multi-path optical heart rate tracker
3-axis accelerometer
Electrical sensor to measure skin conductance
Multipurpose electrical sensors compatible with ECG app and EDA app.
Red and infrared sensors for oxygen saturation
Altimeter
Skin temp sensor
Ambient light sensor
WIFI
NFC
Built in GPS + Glonass
Vibration monitor
Speaker
Microphone

Battery and Power

Battery life up to 7 days. Battery life and charge cycles vary with use, settings, and other factors; actual results will vary.

Battery type: Lithium-polymer
Charge time: (0-100%): Two hours
Charge 12 minutes to get one day of battery life

Memory

Saves 7 days of detailed motion data – minute by minute
Saves daily totals for past 30 days
Stores heart rate data at one-second intervals during exercise tracking and at five-second intervals all other times.

Water resistance

Up to 50 mètres. After getting the band wet, we recommend drying the band.

Materials

This watch includes a band made of a flexible material similar to that used in many sports watches, as well as an aluminium watch case and buckle.

Syncing

Google account will be required.

The Fitbit app is compatible with most popular phones. To set up and use your Fitbit products and services, you must install the Fitbit app on a compatible device running one of the following operating systems:

Apple iOS 14 or higher.
Android OS 8 or higher. See additional tips for Android phones.

Syncing range: Up to 9m

Certain features like smartphone notifications may require Android 8+.
Syncing requires Bluetooth® LE, an internet connection and location permissions granted on the phone

Fitbit Sense 2