(PRE ORDER AUG-SEPT 2019)Solar Diver Powered by light energy-no battery change required 10-month power reserve once fully charged Date calendar Screwdown crown and caseback One-way rotating elapsed timing bezel LumiBrite hands and markers Case diameter: 47.0mm Stainless steel case Water Resistance: Diver's Watch to 200 meters (660 feet). Meets ISO standards and is suitable for scuba diving Silicone strap Caliber V157