Based on the popular tough solar model, the gw2310 has long been a favorite in the g-shock lineup for its classic, utilitarian look and rugged toughness. 46. 4mm stainless steel and bio-based resin case; mineral crystal black dial with easy-read display functions include world time, stopwatch, timer, alarm, calendar, mute feature, and electro-luminescent backlight solar-powered rechargeable battery multi-band atomic timekeeping black bio-based resin band; buckle clasp water-resistant to 200 meters