These Quad Sensor Bluetooth connected G-SHOCK Master of G “GRAVITYMASTER” GRB200 models pack flight mission essential functions into a tough and rugged carbon core guard structure. The watch boasts a carbon core guard structure with the ability to withstand the three gravitational acceleration forces of impact, centrifugal force, and vibration. The carbon monocoque case of the GRAVITYMASTER creates a design that is tough, yet lightweight, while carbon composite materials and monolithic molding enable durability. Quad sensors provide information for altimeter/ barometer, thermometer, compass, and step tracking. Connects to mobile devices.