Parameters Watch Size: 44.5*50*14.8mm Strap Width: 24mm Strap Length: 260mm Weight: 104g Solar Movement Metal Watch case 180 days of battery life 304 stainless steel cover 50m Waterproof 24mm Width Silicone Strap No Need to Replace the Battery Solar-Drive converts any kind of light into energy to power a watch, storing the surplus on a power cell. On a full charge, an Solar-Drive watch runs for months even in darkness with no need for regular battery replacement. It's designed to charge from ordinary everyday light sources like indoor fluorescent lighting and desk lights. You can go about your everyday life confident that your watch will never stop.