Using your G - Shock DW6900RGB - 1 is a breeze. Simply set the time and date when you first get it. It's shock - resistant, so you don't have to worry too much about accidental bumps. For water activities, it can handle up to 200 meters of water pressure, but avoid high - speed water flow like jet skiing. When it comes to battery, it should last about 2 years with a CR2016 battery. Once the battery runs out, have it replaced by a professional to avoid any damage. To keep it looking good, clean the watch regularly with a soft, dry cloth. Don't use harsh chemicals or abrasive materials as they can scratch the resin case and bezel.