Strap for Conquest Automatic 39 Ceramic

The lug width of the Longines Conquest L3.655.4.56.6 is 19 millimetres. This measurement is taken by positioning a digital calliper between the inner lugs of the case, from shoulder to shoulder. The spring bars have a standard diameter of 1.6mm. When purchasing a replacement strap, it is essential to verify that the measurement falls within the tolerance of ±0.2mm, specifically between 18.8 and 19.2 millimetres.

For the Conquest L3.655.4.56.6, we recommend a dark brown or black alligator strap for a formal-sporting aesthetic, or vegetable-tanned calf leather for daily wear with natural patina development over time. The regular scaling of alligator creates a linear texture consistent with the minimalist ceramic and stainless steel case design. For water-intensive applications, a rubber strap with 19mm width ensures complete water resistance. NATO straps, although compatible, compromise the elegant character of the model.

To change the strap on the Conquest L3.655.4.56.6, first remove the spring bars from the case lugs using a dedicated spring bar tool. Position the tool at the lower end of the spring bar, apply gentle upward pressure until the internal spring disengages, then extract the bar from the case. The new 19mm lug width strap is inserted by sliding the spring bar through the lug holes and re-engaging the ends in their original seats. Professional inspection by a qualified watchmaker is recommended if you lack experience with this operation.

Yes, numerous aftermarket straps compatible with the 19mm lug width of the Conquest L3.655.4.56.6 are available online. MilanoStraps offers a specialised collection of 19mm straps crafted from alligator, shell cordovan, vegetable-tanned calf, and technical fabrics, customisable in width, colour, and buckle type. Compatibility is guaranteed by verifying that the strap is specifically designated for 19mm lugs and that the spring bars have a 1.6mm diameter. Casati Milano also creates bespoke straps with personal leather selection.

The durability of a leather strap depends on the species, tanning method, and intensity of use. A strap in vegetable-tanned calf leather has a lifespan of 3 to 5 years with moderate daily wear and bi-annual maintenance using colourless conditioner. Shell cordovan resists wear for 5 to 7 years owing to its natural fibrous structure and requires minimal maintenance. Alligator, whilst more delicate, maintains integrity for 4 to 6 years under normal conditions. Protection from stagnant water and prompt drying after prolonged immersion significantly extend the working life of the strap.