Track steps, distance, calories burned and active minutesSee stats and time with a bright OLED tap display;Battery life up to 5 days. Battery life and charge cycles vary with use, settings, and other factors; actual results will vary. Radio transceiver: Bluetooth 4.0Automatically track how long and how well you sleep, and set a silent, vibrating alarm ; The Fitbit Alta wristband is made of a flexible, durable elastomer material similar to that used in many sports watches. The Alta tracker and clasp are made with surgical-grade stainless steel ; Syncs Wirelessly : Android and Windows devices.Personalize with interchangeable metal, leather and classic bands sold separately ; Battery life up to 5 days. Battery life and charge cycles vary with use, settings, and other factors; actual results will vary. Battery type: Lithium-polymer. Charge time: One to two hours.Get call, text and calendar notifications at a glance when phone is nearby