General Info and Specifications

Sensors and Components

Fitbit Sense 2 contains the following sensors and motors:

  • Multi-path optical heart rate tracker
  • Electrical sensor to measure skin conductance (cEDA) for stress detection
  • Multipurpose electrical sensors compatible with the ECG app and EDA Scan app
  • Red and infrared sensors for oxygen saturation (SpO2) monitoring
  • Gyroscope
  • Altimeter, which tracks altitude changes
  • 3-axis accelerometer, which tracks motion patterns
  • On-wrist skin temperature sensor
  • Ambient light sensor
  • NFC
  • Built-in GPS receiver + GLONASS, which tracks your location during a workout
  • Vibration motor
  • Speaker
  • Microphone
  • WiFi (deactivated, cannot be turned on)


The band that comes with Sense 2 is made of a flexible, durable elastomer material similar to that used in many sports watches.

The housing and buckle on Sense 2 are made of aluminum. While aluminum can contain traces of nickel, which can cause an allergic reaction in someone with nickel sensitivity, the amount of nickel in all Fitbit products meets the European Union's stringent Nickel Directive.

Wireless technology

Sense 2 contains a Bluetooth 5.0 radio transceiver and NFC chip.

Haptic feedback

Sense 2 contains a vibration motor for alarms, goals, notifications, reminders, and apps.


Sense 2 contains a rechargeable lithium-polymer battery.


Sense 2 stores your data, including daily stats, sleep information, and exercise history, for 7 days. See your historical data in the Fitbit app.


Sense 2 has a color AMOLED display.

Band size

Band sizes are shown below. Note that accessory bands sold separately may vary slightly.

Small band Fits a wrist between 5.5 - 7.1 inches (140 mm - 180 mm) in circumference
Large band Fits a wrist between 7.1 - 8.7 inches (180 mm - 220 mm) in circumference

Environmental conditions

Operating temperature

14° to 113° F
(-10° to 45° C)

Non-operating temperature

-4° to 14° F
(-20° to -10° C)

113° to 140°F
(45° to 60° C)

Charging temperature 32° to 95° F
(0° to 35° C)
Water resistance Water resistant up to 50 meters
Maximum operating altitude 28,000 feet
(8,534 m)

Learn more

To learn more about your watch, how to track your progress in the Fitbit app, and how to build healthy habits with Fitbit Premium, visit

Return policy and warranty

Find warranty information and the return policy on our website.