Strap for Heritage Legend Diver 39 Stainless Steel / White / Bracelet

The lug width of the L3.764.4.16.6 is 20mm. This measurement was selected by Longines to maintain the historical proportions of the 39mm case without creating visual imbalance. To verify strap compatibility, measure with a digital calliper the internal distance between the two lugs: it must be exactly 20mm.

There is no universal choice—it depends on intended use. For formal elegance and longevity (10-15 years), black or dark brown alligator is ideal. For artisanal authenticity with evolving patina, vegetable-tanned calf leather is preferable. For intensive water use and practicality, rubber straps with military-style lugs offer immutability to chlorine and saltwater. Shell cordovan provides a middle ground between elegance and wear resistance.

The Legend Diver uses standard push-fit pins (not quick-release). Equipped with a spring bar tool, gently push inward on the small metal rod securing the strap to the lugs, withdraw the pin and slide off the old strap. Insert the new strap aligning it perfectly, then reinsert the pin until it clicks into place. Procedure recommended at specialist watchmaker to avoid scratches to the case.

Yes, provided they are certified at 20mm. Compatibility is guaranteed only if the strap has been manufactured to exactly this width and thickness does not exceed 5mm (beyond that causes lug interference). Choose suppliers offering return guarantees and compatibility certificates. Custom-made straps from Casati Milano guarantee perfect fit and 18-month warranty.

Durability varies depending on material quality and usage conditions. A quality alligator strap lasts between 10 and 15 years if subjected to regular maintenance (six-monthly oiling). Vegetable-tanned calf leather lasts 6-10 years if exposed to moderate humidity and cared for monthly. Exposure to water, salty sweat and extreme temperatures reduces lifespan. Rubber straps, conversely, maintain structural integrity for 15-20 years.