G-Shock Watch Full Metal Black GMW-B5000G-1ER. An innovative core guard case structure means the watch is tougher than ever. Notable advancements in the technology offering include Multi Band 6 radio control which ensures the most accurate timekeeping, while Bluetooth Connectivity means you can easily switch your watch time settings from time zone to zone while you travel the world. Solar power means that despite the added technological features your watch has efficient watch operation, as well as up to two years power reserve.