Wrist Size : 140-210 mm Watch Strap : 22 mm leather strap Dimensions : Watch: 47 mm × 47.5 mm × 14.99 mm , Earbuds: 21.8 mm × 10.3 mm × 10.3 mm Screen size : 1.43 inches, AMOLED color screen Resolution : 466 × 466, PPI 326 Sensor : 6-axis inertial sensors (acceleration sensor and gyroscope sensor), optical heart rate sensor 5.0, ambient optical sensor, Hall effect sensor, capacitive sensor, and bone conduction component (VACC). System Requirements : Phones running Android 7.0 or later,EMUI 12.0 or later,Phones running iOS 9.0 or later Water resistance : The earbuds are IP54-rated. Water may enter the earbud compartments when the watch cover is opened and closed, so please try to keep the compartments dry.