Strap for Spirit Automatic 40 Silver / Strap XL

The lug width of the Longines Spirit L3.810.4.73.4 is 21mm. This dimension corresponds to the internal distance between the two spring bars that support the strap. This is a specific measurement for this model and not a standard commercial size, so it is essential to verify compatibility before purchasing an aftermarket strap. Every strap must respect exactly these 21mm to guarantee perfect fit to the watch.

The Longines Spirit L3.810.4.73.4 pairs perfectly with straps in vertically-cut alligator leather, vegetable-tanned calf, shell cordovan, and butadiene rubber. Black alligator with pearl-grey stitching emphasizes the formal and aviatory character; cognac calf develops personal patina over time; shell cordovan offers durability and intrinsic lustre. Rubber is ideal for sports use or seasonal wear. The choice depends on the context of use and personal aesthetic preferences.

Changing the strap on the Longines Spirit L3.810.4.73.4 requires extraction of the two spring bars that support the current strap. Using a dedicated tool (spring bar tool), positioned perpendicular to the case, push the bar towards the centre until it is freed from its seat. The new 21mm strap is inserted by aligning the lugs with the spring bar seats, which will lock automatically. If unsure, consult a professional watchmaker or the Casati Milano atelier.

Yes, the Longines Spirit L3.810.4.73.4 is fully compatible with quality aftermarket straps, provided they respect the 21mm lug width. Milanostraps.it offers a wide selection of artisanal 21mm leather straps customizable in material, colour and stitching. For a bespoke experience, the Casati Milano atelier creates custom straps with personal leather selection and 18-month warranty.

The lifespan of a leather strap depends on the quality of the leather, frequency of use and maintenance. A vegetable-tanned calf or quality artisanal alligator strap lasts 3-5 years with regular daily use. Shell cordovan, due to its inherent robustness, can last even longer. Butadiene rubber has a longer lifespan in humid environments. Proper drying after water exposure and storage in a dry environment significantly extend the life of the strap.