Tracks calories burned, distance traveled, heart rate, sleep quality and steps taken Automatically recognizes and displays your day by activity and sport. Automatically recognizes your sleep and knows how much you need tonight to be fully rested and at your best tomorrow. LED display Waterproof design Built-in rechargeable lithium-ion battery Package Contents JayBird Reign Advanced Activity Tracker Large and extra-large sportbands, size 4 and 5 premium band straps Rechargeable lithium-ion battery Owner's manual