CASIO gshock GM-5640GEM-1JR GM-5640GEM-1 limited model 20ATM watch 2023.01 releasedProduct Highlights Authentic CASIO watch. Japanese domestic market (JDM) edition. Product Description h2> ELEGANCE AND TECHNOLOGY G Shock is a line of watches manufactured by Japanese electronics company Casio, designed to resist mechanical shock and vibration. G Shock is an abbreviation for Gravitational Shock. The watches in the G Shock line are designed primarily for sports, military and outdoors oriented activities; nearly all G shocks are digital