Seiko 5 Sports SRPJ85K1 - 36.4mm Men's Automatic Field Watch. Compact and durable, the Seiko 5 Sports SRPJ85K1 features a 36.4 mm stainless steel case, black dial with day-date display, and Seiko's reliable automatic 4R36 movement - engineered for everyday adventure, precision, and rugged field-watch styling.. Overview Design & Build Automatic Movement Everyday Functionality Specifications. Compact Size, Tactical Performance. The SRPJ85K1 stands out with its smaller 36.4 mm case - perfect for those who prefer a streamlined, military-inspired field watch. Its black dial, bold indices, and khaki nylon strap create a rugged and functional aesthetic suited for both urban and outdoor wear.. Design & Build Quality. Built with a durable stainless steel case and paired with a strong khaki nylon strap, this model is designed for resilience. The black dial provides excellent legibility thanks to luminous hands and markers, while the day-date window adds practical everyday usability.. Reliable Automatic Movement. Powered by the proven Seiko Calibre 4R36, the SRPJ85K1 offers automatic and manual winding, hacking seconds, and a 41-hour power reserve. The movement combines durability with everyday precision, making it ideal for active lifestyles.. Versatile Everyday Wear. With 100 meters of water resistance, this model is ready for swimming, outdoor exploring, and daily activities. Its compact case fits comfortably on all wrist sizes, while the military-inspired styling adds a bold yet classic character to any outfit.. Specifications. Brand. Seiko. Model. SRPJ85K1. Barcode / EAN. 4954628249135. Gender. Men. Band Colour. Brown. Band Material. Stainless Steel. Case Colour. Silver. Case Diameter. 36 mm. Case Material. Stainless Steel. Dial Colour. Black. Movement. Automatic. Water Resistance. 10 ATM / 100 m. Features. Day-date display, luminous hands & markers, Hardlex crystal