The Citizen Eco-Drive Promaster Professional Diver watch is used for mixed gas diving with its 6mm non-reflective curved crystal, ratcheted elapsed-time bezel, screw-back case and screw-down crown, and reinforced urethane band and extender, with a carrying case for the wetsuit strap extension. Crafted in stainless steel with luminous accents, this remarkable timepiece is as resilient as it is handsome, with water-resistance up to 30 bar. Featuring Citizen’s Eco-Drive technology, the watch is powered by light, any light, never needing a battery. Caliber number B873.<ul><li>48mm stainless steel case with a Promaster screw-down crown, a one-way rotating ratcheted elapsed time bezel, and a screw-back case</li><li>Impact and shatter-resistant anti-reflective 6mm curved mineral crystal</li><li>Lug Width: 29mm</li><li>Black dial with a date window at 3 o’clock, a minute track, and luminous hands and hour markers</li><li>Black reinforced polyurethane strap with a buckle and extender</li><li>Strap Length: 206.375mm</li><li>Caliber B873 3-hand Eco-Drive movement powered by any light source, continuously and sustainably, eliminating the need to replace watch batteries</li><li>Water-resistant up to 300 meters/30 bar (scuba diving)</li><li>Citizen Style #: BJ8050-08E</li></ul>