Strap for Spirit Automatic 40 Green / Bracelet

The Longines Spirit L3.810.4.03.6 features a lug width of 21mm. This measurement represents the distance between the two spring bar holes on the watch lugs. To verify this dimension, carefully remove the spring bars from the lugs and measure the exact distance between the holes using a digital calliper or ruler—it should be precisely 21mm with no appreciable tolerance.

The Longines Spirit L3.810.4.03.6 pairs excellently with straps in African alligator (vegetable-tanned), satin calf, shell cordovan, or high-quality textiles such as cotton gabardine or ballistic nylon in keeping with its aviator heritage. Material selection depends on intended use: vegetable-tanned leather for understated elegance, textiles for sporting practicality. Avoid excessively padded straps that would visually overwhelm the 40mm case.

Remove the spring bars (removable lugs pins) from the watch lugs using a small flathead screwdriver or dedicated spring bar tool. Once extracted, the original strap will detach. Insert the same pins into the new strap (which must feature the same 21mm lug width spacing), then carefully reinsert the spring bars into the lugs of the case, ensuring they seat firmly. Verify correct strap attachment before wearing the watch.

Any strap with a 21mm lug width is compatible with the Longines Spirit L3.810.4.03.6. On milanostraps.it you will find a curated collection of 21mm straps customisable in vegetable-tanned leather, alligator, rubber, and textiles. Each strap is constructed to integrate seamlessly with the case without creating angular tensions and can be adjusted in length to your wrist size.

A high-quality leather strap (vegetable-tanned, alligator, or cordovan) worn regularly has an average lifespan of 3–5 years before replacement is warranted. Longevity depends on frequency of wear, UV exposure, humidity levels, and maintenance care (periodic cleaning, optional protective treatments). The Casati Milano atelier guarantees 18 months on bespoke straps, a protection that covers construction defects and permits preventative replacements.