Fitbit claims six days of battery life on the sense, and that's close to accurate in my testing with always-on display ...
connectivity: wi-fi (802.11b/2.4ghz), bluetooth 5.0, nfc, gps
battery: up to 6 days
display: 1.58-inch 336 x 336 oled
sensors: temperature, eda, ecg, heart rate, blood oxygenation (spo2), accelerom
Condition: Brand New