GA-2100 SERIES Carbon Core Guard structure Ever since the first DW-5000C went on sale back in 1983, G-SHOCK has continued to push the limits of timekeeping toughness while creating new and original designs. These new models embody these efforts in an attractively thin configuration. These new models inherit the octagon form that was also employed for the original DW-5000C. Analog-digital timekeeping comes packed into a no-nonsense simple design without sacrificing G-SHOCK level toughness. High-strength resin material, which is reinforced with carbon fibers, makes it possible to create a case that is a mere 11.8 mm thin, which is the thinnest among G-SHOCK combination models. Neobrite: Only for GA-2100-1A, GA-2100-4A Carbon Core Guard Structure A new carbon core guard structure protects the module by enclosing it in a carbon case. The case is made of fine resin embedded with carbon fibers for outstanding strength and crack resistance. Case / bezel material: Carbon / Resin? Resin Band Mineral Glass Shock Resistant 200-meter water resistance Double LED light LED light for the face (Super illuminator, selectable illumination duration (1.5 seconds or 3 seconds), afterglow) LED backlight for the digital display (Super illuminator, selectable illumination duration (1.5 seconds or 3 seconds), afterglow) World time 31 time zones (48 cities + coordinated universal time), daylight saving on/off, Home city/World time city swapping 1/100-second stopwatch Measuring capacity: 00'00''00~59'59''99 (for the first 60 minutes) 1:00'00~23:59'59 (after 60 minutes) Measuring unit: 1/100 second (for the first 60 minutes) 1 second (after 60 minutes) Measuring modes: Elapsed time, split time, 1st-2nd place times Countdown timer Measuring unit: 1 second Countdown range: 24 hours Countdown start time setting range: 1 second to 24 hours (1-second increments, 1-minute increments and 1-hour increments) 5 daily alarms Hourly time signal Hand shift feature (Hands move out of the way to provide an unobstructed view of digital display contents.) Full auto-calendar (to year 2099) 12/24-hour format Button operation tone on/off Regular timekeeping Analog: 2 hands (hour, minute (hand moves every 20 seconds)), 1 dial (mode) Digital: Hour, minute, second, pm, month, date, day Accuracy: 15 seconds per month Approx. battery life: 3 years on SR726W 2 Size of case : 51.248.714.1mm Total weight : 64g