Fitbit Charge 2 Activity Tracker + Activity Tracker Wristband (Small or Large)

Small wristband: Fits wrists 5.5"-6.7" in circumference.
Large wristband: Fits wrists 6.7"-8.1" in circumference.
Wristband width: 0.84".
Memory: Saves up to 7 days of workout data.
Battery life: Up to 5 days.
Charge time: One to two hours.