Connected with phone, then the watch work; Button cell CR2430/13month lifetime of Battery; Bluetooth 4.0 of Connection; IOS 8.0/Android 4.3 or above of Compatible Operating Systems; Ivory White (Crack Oily Calf)/Nylon Leather strap; Pin buckle; 11 mm Silver Stainless Steel Case Thickness; Water resistant to 5 ATM.