Strap for Spirit Automatic 37 Blue / Bracelet

The Longines Spirit L3.410.4.93.6 has a lug width of 20mm. This specific measurement is essential for compatibility: straps measuring 18mm or 22mm will not fit properly in the case lugs. When ordering an aftermarket strap, always verify that it is explicitly marked as "20mm lug width" to avoid purchasing errors.

For this pilot-tool watch, the ideal strap depends on use: alligator in brown or cognac amplifies the vintage pilot aesthetic with sophisticated elegance; vegetable-tanned calf leather develops extraordinary aged patina; a grey-green NATO canvas maintains sporty authenticity. The right choice combines personal taste with frequency of wear (formal, daily, or sports).

The change is made by removing the spring bars that secure the strap to the case lugs. Place the watch on a soft surface, use a dedicated tool (or small flathead screwdriver) to compress the pin and release it, then remove the old strap. Insert the new strap by aligning the holes with the lugs and press until it clicks into place. A straightforward and reversible operation when handled with care.

Yes, the model accepts any strap with an exact 20mm lug width. Many artisanal manufacturers produce 20mm straps customizable in leather, colour, thread, and buckle. Verify that the strap clearly states "20mm" and that the lugs are proportioned to the 37mm case diameter, without excessive lateral protrusion.

A quality leather strap (alligator, calf, shell cordovan) lasts an average of 3–5 years with daily wear, extendable to 7–10 years with regular maintenance (cleaning, proper drying after perspiration, annual conditioning). NATO canvas is more durable (8–12 years), while rubber resists up to 10 years. Ageing is natural and sometimes desired: many enthusiasts keep the same strap for decades, appreciating its developing patina.