Wear OS by Google, GPS, 5 Bar WR, Mil-Standard 810 G Durability, 50M Water ResistantDigital compass, Altimeter, Barometer, Activity Tracker, Dual Layer LCD Structure, Original Watch Face, Casio Moment Setter, Microphone, Timepiece modeQuartz MovementCase Diameter: 55mmWater resistant to 50m (165ft: in general, suitable for short periods of recreational swimming, but not diving or snorkelinglimited app functionality with iPhonesLow-temperature resistance (-10℃)Measurement Accuracy: within +/-75m (+/- 250ft)