As substantial and strong as its nickname suggests, this Seiko Prospex Diver’s Sumo Chronograph is designed to take on even your most challenging adventures. The powerful solar battery is charged by both natural and electric light. At A Glance  Presented on a black silicone accordion strap 44.5mm stainless steel case with a blue uni-directional rotating bezel and 200m water resistance Sapphire crystal Blue dial with LumiBrite dot hour markers Date window at 4:30 Three chronograph sub-dials Battery charge indicator and overcharge prevention function Powered by a solar movement Up to 6 months battery life when fully charged