Momentum Men's 1M-SP40US2 Topograph Altimeter Sapphire Blue Dial Black Leather Watch Quartz-analog-altimeter movement Synthetic-sapphire crystal Case diameter: 45.6 mm 316l-stainless-steel case; gloss-blue dial; day function Water resistant to 330 feet (100 M): suitable for snorkeling, as well as swimming, but not diving