Upgrade the retro look you love with the octagonal GA-2100 line which inherits the design concept of the very first G-SHOCK but now with Smartphone Link and Tough Solar power.Shock Resistant.Tough Solar (Solar powered).Bluetooth- Connects to a smartphone and automatically adjusts the time.Carbon Core Guard structure.200-meter water resistance.Neobrite.World time.5 daily alarms.stopwatch.Countdown timer.Full auto-calendar (to year 2099).Case size 48.5 - 45.4 - 11.9 mm.7 months on rechargeable battery (operation period with normal use without exposure to light after charge).