Seiko Prospex Speedtimer SPB513J1 – Automatic 3 Days The Seiko Prospex Speedtimer SPB513J1 combines Seiko’s motorsport heritage with a distinctive 1970s-inspired design. Powered by the Calibre 6R55 automatic movement, it offers an impressive 72-hour (3-day) power reserve. The watch features a 39.5 mm stainless-steel case, curved sapphire crystal and a distinctive dial with subtle orange accents. Its inner rotating countdown bezel, operated by the crown at 4 o’clock, adds both functionality and character. Key specifications: • Reference: SPB513J1 • Calibre: 6R55 Automatic • Power reserve: 72 hours / 3 days • Case diameter: 39.5 mm • Curved sapphire crystal • Rotating countdown bezel • Stainless-steel bracelet • Water resistance: 200 m / 20 bar A refined mechanical Speedtimer combining vintage Seiko design, modern performance and excellent everyday versatility.