Strap for Spirit Automatic 39 Stainless Steel / Black / Leather

The lug width of the Longines Spirit L3.809.4.53.2 is 20 millimetres. This measurement represents the distance between the two attachment pins on the case where the strap seats. To verify it, position a calliper between the inner lugs of the case: the value obtained is what you need to select a compatible strap. All straps with a 20 mm lug width will fit this model correctly.

The Longines Spirit L3.809.4.53.2, with its aviator heritage, pairs excellently with character-driven leather straps: alligator in dark tones (brown or black), calf with vegetable tanning that develops patina over time, or structured rubber for a functional approach. A chocolate-brown alligator creates visual continuity with the austere dial; vegetable-tanned calf offers natural aesthetic evolution; rubber remains the pragmatic choice for intensive use. A khaki canvas NATO strap also maintains coherence with the model's military heritage.

Strap replacement requires a specific tool: a spring bar tool. Position the watch on a stable surface with the strap facing upwards. Insert the tool into the space between the case and strap, gently compressing the internal spring until the pin releases. Repeat on the other side. To fit the new strap, align the pins with the holes and push until you hear a click of engagement. If you lack experience, entrust this task to a jeweller or specialised atelier such as Casati Milano, which offers the service by appointment.

Yes, absolutely. Any strap with a 20 mm lug width is compatible with the Longines Spirit L3.809.4.53.2. Milanostraps.it offers a collection of artisanal 20 mm straps crafted in premium materials (alligator, calf, shell cordovan, rubber) with customisable finishes. Choosing a quality aftermarket strap does not compromise the watch; on the contrary, it enables greater aesthetic and functional versatility compared to the factory strap.

The lifespan of a leather strap depends on the quality of the leather and level of maintenance. A top-tier alligator or shell cordovan with vegetable tanning maintains structural integrity for 5–7 years of regular wear, whilst developing a desirable patina. A softer calf may require replacement after 3–4 years. Structured rubber is virtually permanent, provided it is not exposed to extreme temperatures. Casati Milano guarantees 18 months on all artisanal straps; periodic maintenance (gentle cleaning, leather conditioning) significantly extends useful life.