Descended from Seiko's first sports watch from 1959, the SPB507 Alpinist features the iconic green dial and gold accents pulled from the archives. The 39.5mm stainless steel case has a super-hard coating, with the Alpinist logo prominently displayed on the dial. Inside is the 24-jewel automatic movement beating at 21,600 vibrations per hour with a 72-hour power reserve and manual winding capability. The rotating inner compass bezel handles navigation duties, while the brown calf leather strap from an LWG-certified tannery pairs with 200-meter water resistance for field use.