Strap for Flagship 38.5 Black Diamond

The Longines Flagship L4.874.4.57.2 features a lug width of 20 mm. This specification is critical: the strap must be manufactured to this exact width, measured between the lugs on the case. Using straps of different dimensions (18 mm or 22 mm) will result in either excessive slack or impossibility of fitting without forcing the case.

Alligator is the primary choice: uniform texture, understated elegance, proven durability. Vegetable-tanned calf leather is the versatile alternative, developing natural patina over time. Shell cordovan represents the selection for those seeking rarity and chromatic depth. For informal contexts, satin NATO or vulcanised rubber maintain the functional seriousness of the watch.

The Flagship uses standard 20 mm lugs. Acquire a lug removal tool (pin pusher) of suitable size. Position the watch on a stable surface, locate the spring bar pin securing the strap to the case, gently push the pin inward using the pin pusher, remove the strap. Repeat on the opposite lug. Insert the new strap by aligning the lug with the hole and reverse the procedure. If uncertain, consult a qualified watchmaker.

Yes, the Flagship accepts any strap manufactured for a 20 mm lug width, regardless of manufacturer. Artisanal Italian-made straps from milanostraps.it are fully compatible: all 20 mm collection models mount seamlessly on this watch. Avoid straps with incompatibly shaped lugs or overly thick buckles that might contact the case.

A quality alligator strap with vegetable tanning lasts 5–8 years with ordinary maintenance (periodic brushing, annual natural wax treatment, protection from salt water). Vegetable-tanned calf leather lasts 4–6 years before requiring replacement due to natural wear of the keeper. Shell cordovan, being more robust leather, may last 10+ years. Lifespan depends on frequency of use and environmental conditions (humidity, direct sunlight, perspiration).