Rip Curl Men's A2376-BLK Beacon Polyurethane Black Watch 316L stainless steel case: the highest grade of stainless steel for water resistance, strength and non-corrosion in a marine environment Jeweled movements: synthetic rubies which serve as bearings for gears in watches. This reduces torque and friction allowing your watch to run more accurately for longer Case diameter: 42 mm Water-resistant to 330 feet (100 M)