Runtastic Moment Activity and Sleep Tracking Watch 24/7 timekeeping & activity tracking. Automatic time sync: provides information on daily steps, distance, calories burned, sleep duration & cycles etc. No charging necessary: long lasting lithium battery. "High quality: Stainless steel case ( 1.65in / 42mm)Scratch-proof mineral glass, Leather strap, waterproof up to 300ft/ 100m". Supported devices: iPhone 4S/5/5s/5c/6/6 Plus, Android: Bluetooth Smart Ready devices running Android 4.3 or higher, Windows Phone: Bluetooth Smart Ready devices running WP8.1 or higher.