Important Notice: This 'NOS' authentic, discontinued timepiece is unworn inventory that has remained in storage for a prolonged period and is not equivalent to a factory-fresh modern retail watch. Due to age and historical handling, the item may exhibit "storage wear" such as fine hairline scratches or minor abrasions. Buyers should note that internal lubricants may have dried or gaskets degraded, so a professional service and pressure test are recommended to ensure optimal performance.
Introduced in 2020 as part of the redesigned Seiko 5 Sports line, the SRPE51 removed the dive bezel to offer a more versatile daily watch, earning the enthusiast moniker "DressKX."
The 40mm stainless steel case features a sunburst grey dial framed by a fixed smooth bezel, applied lumed indices, and a day-date window at three o'clock. Powering the watch is the automatic Caliber 4R36, operating at 21,600 vibrations per hour with a 41-hour power reserve and manual winding capabilities.
Established in 1881 by Kintarō Hattori, Seiko is defined by its principle of complete vertical integration, manufacturing every single component of its timepieces in-house. They were the primary catalyst of the "Quartz Crisis" with the commercial release of the 1969 Astron—the world’s first quartz watch—the brand simultaneously advanced mechanical horology, developing one of the first automatic chronographs and pioneering high-frequency movements to challenge Swiss standards.
Seiko's relentless innovation continues with proprietary technologies like Spring Drive, which blends mechanical power with quartz precision. This technical mastery underpins Seiko's legacy in creating archetypal and exceptionally durable tool watches, particularly in the domain of professional diving.
Overall Grade: 8 / 10 | New Old Stock, Visible Wear Production: 2026 Contents: Full-set Genre: Sports Watch
Size: 40mm Thickness: 12mm Lug Width: 20mm
Case: Stainless steel, mirrored sides, brushed lugs, visible wear Bezel: Fixed, smooth bezel, mirrored, visible wear Dial: Sunburst grey dial, applied markers (lumed), day-date display Hands: Lumed SKX-style handset
Crown: Stainless steel, push/pull crown, visible wear Crystal: Hardlex crystal, visible wear Bracelet: Stainless steel bracelet, visible wear Caseback: Stainless steel, exhibition caseback, screw-on, visible wear Movement: Automatic Caliber: 4R36