Move to the beat of you with Fitbit Alta HR-the heart rate wristband that motivates you to reach your goals in style. Jumpstart your fitness journey with PurePulse heart rate and SmartTrack automatic exercise recognition. Track your all-day activity and sleep, stay connected with smartphone notifications, and get friendly Reminders to Move. Using Bluetooth LE wireless technology, Fitbit Alta HR sends smartphone notifications and syncs automatically to computers and 200+ mobile devices. Smartphone notifications may require Android 5.0+. Syncing range: Up to 30 feet Syncing requires Bluetooth LE and Internet connection. Windows 10 computers that do not have Bluetooth LE will need a wireless sync dongle in order to sync. Syncs with Mac OS X 10.6 and up, iPhone 4S and later, iPad 3 gen. and later, Android 4.4 and later, and Windows 10 devices. The Fitbit Alta HR wristband is made of a flexible, durable elastomer material similar to that used in many sports watches. The tracker is made with surgical-grade stainless steel, and the buckle is made with aluminum. The Alta HR gunmetal tracker is made with premium PVD plating, and the rose gold tracker is plated with 22k rose gold.