With the RELAY HR Wireless Activity plus Sleep Tracker you can reach your fitness and sleep goals as well as stay on top of your HR, texts and calls you get to your mobile phone.WEGO Relay HR Activity and Sleep Tracker:On demand Optical HR ReadingCaller ID/Text Relay DisplayBattery Level Indicator/Date on Main DisplayButton Free Syning to Join WeGo AppAuto-Sleep FunctionWatch Buckle and StrapSilent Vibration Alarm for Goal Achievement and Waking UpDisplays Time, Steps, Calories, Distance, Activity Time, Goal%, and SleepWireless Bluetooth Sync and transfer of data to Join WeGo App Battery lasts up to 7 days