Inspired by the nighttime ocean, Seiko's limited edition line of Prospex Black Series diving watches is defined by their black DLC-coated stainless steel cases. The most limited of the lineup is the SLA035J1 Professional model, with a 44.3mm case, water resistance to 1,000 feet, and an 8L35 automatic movement. Just 600 examples will be made. Joining it are the SPB125J1 "Sumo", a 660-foot, 45mm model with a 6R35 automatic movement, and the SSC761J1, a solar-powered 44.5mm chronograph also offering water resistance to 660 feet. The Sumo is limited to 7,000 examples, while the latter is limited to 3,500.