Philip Stein Men's 'Signature' Quartz Stainless Steel and Leather Casual Watch, Color:Black (Model: 3-NGW-an) Quartz movement Stainless steel, 56x38mm Sapphire-coated curved mineral crystal The proprietary natural frequency technology inside Philip Stein watches and jewelry is tuned to pick up natural frequencies that are believed to be beneficial to life and overall well-being Water resistant to 165 feet (50 M): suitable for swimming and showering