Citizen Men's AV3006-09E The Signature Collection Eco-Drive Moon Phase Flyback Chronograph Watch Eco-drive is fueled by light, any light, so it never needs a battery. 1/5 second chronograph measures up to 12 hours Moon phase indicator Dual-coated anti-reflective sapphire glass crystal. 12/24 hour time Water resistant to 330 feet (100 M): suitable for snorkeling, as well as swimming, but not diving