As of my last knowledge update in January 2022, here are the detailed specifications for the Fitbit Sense:

Fitbit Sense:

Design:

• Dimensions: 40.48mm x 40.48mm x 12.35mm
• Weight: Approximately 30.48 grams (without band)
• Materials: Aerospace-grade aluminum case and a stainless steel ring

Display:

• Type: AMOLED
• Size: 1.58 inches
• Resolution: 336 x 336 pixels
• Brightness: Up to 1000 nits

Sensors:

• EDA (Electrodermal Activity) Sensor
• ECG (Electrocardiogram) App
• PPG (Photoplethysmogram) heart rate sensor
• Skin temperature sensor
• Ambient light sensor
• 3-axis accelerometer
• Gyroscope
• Altimeter
• GPS