G-Shock Watch Gravitymaster GR-B200-1A9ER. The G Shock Series Master of G watches are renowned for delivering powerful functions designed to operate under severe environments on land, on the sea, and in the air. Now the new matte black color of this series adds a selection of watches with a distinctively adult character. Buttons, the buckle, the band loop, the crown, the bezel, and other metal parts are gold ion plated. The result is a collection of beautiful timepiece that maintain all the original toughness of the G Shock brand.