- Battery type: Lithium-polymer
- Charge time: (10-80%): Approximately 40 minutes
- Fast charging: 1 day of battery life in 12 minutes
- Radio transceiver: Bluetooth®
- Built-in GPS + GLONASS
- Red and infrared sensors for oxygen saturation (SpO2) monitoring
- 3-axis accelerometer
- Altimeter
- Wi-Fi (802.11b/g/n 2.4GHz)
- Ambient light sensor
- Microphones
- Speaker
- NFC
- Vibration motor
- Optical heart rate sensor
- Device temperature sensor (skin temperature variation available in the Fitbit app)
- Saves 7 days of detailed motion data – minute by minute
- Saves daily totals for past 30 days
- Stores heart rate data at 1-second intervals during exercise tracking and at 5-second intervals all other times
- Band Size (Small): Fits wrist 5.5" - 7.1" in circumference
- Band Size (Large): Fits wrist 7.1" - 8.7" in circumference