Citizen Men's BL5466-54H The Signature Collection Eco-Drive Octavia Perpetual Calendar Chronograph Watch Eco-drive is fueled by light, any light, so it never needs a battery. 1/20 second chronograph measures up to 60 minutes Perpetual calendar Dual-coated anti-reflective sapphire glass crystal. Dual time Water resistant to 330 feet (100 M): suitable for snorkeling, as well as swimming, but not diving