Seiko
Prospex Divers SPB237— lug 20mm

The lug width of the SPB237 is 20 mm. This measurement represents the internal distance between the two lugs of the case and determines compatibility with aftermarket straps. Verification is essential before purchase: position a digital calliper between the lugs, measuring from inside to inside, excluding any decorative protrusions.

Selection depends on use and wrist preferences. For formal elegance, we recommend a vegetable-tanned calf leather in dark brown on a stainless steel deployante, which dialogues with the case's substantial mass. To emphasise diving functionality, a NATO in grey or military-green canvas is ideal. For wet environments, matte rubber remains the most practical choice, guaranteeing grip and rapid drying.

The SPB237 uses spring bars that fasten the strap to the case lugs. With a spring bar tool, press inward on one side of the bar until it yields, removing it gently. Align the new strap hole with the bar and press in until it clicks. Repeat on the opposite side. Straightforward but requires precision to avoid scratching the case.

Yes, any strap with certified 20 mm lug width is mechanically compatible with the SPB237. Compatibility is guaranteed if the internal width of the strap (between the two spring bar holes) matches exactly 20 mm. Always verify strap thickness as well: if excessive, it may not slide correctly through the lugs.

Longevity depends on leather quality, usage conditions and humidity exposure. Superior vegetable-tanned calf leather, worn primarily in dry environments and subjected to regular maintenance, can last 5-7 years. Frequent exposure to saltwater, intense perspiration or direct sunlight significantly reduces lifespan. To extend durability, we recommend periodic application of protective balms and immediate drying after water contact.