Strap for Conquest 29.5 Automatic Stainless Steel White

The lug width of the Longines Conquest L3.276.4.16.6 is 15mm. This dimension represents the internal distance between the two spring bars that secure the strap to the watch case. Accurate measurement using a digital calliper is essential to ensure strap compatibility, as 15mm is a non-standard size in the contemporary market and must not be confused with similar dimensions such as 16mm.

For the Longines Conquest L3.276.4.16.6, straps in fine-grained alligator, vegetable-tanned calf leather, thick NATO fabric, or natural rubber are recommended. Dark alligator enhances formal aesthetics, vegetable-tanned calf develops organic patina over time, NATO offers sporty versatility, whilst rubber ensures seasonal comfort. Shell cordovan is discouraged due to its density and difficulty in adapting to compact lug widths.

To change the strap, position the watch on a soft surface with the case facing upward. Utilise a dedicated spring bar removal tool or a small flathead screwdriver to gently press downward one of the elastic pins that support the lug. Once the pin is removed from one side, carefully extract the lug from the case. Proceed in reverse to install the new strap, ensuring that the pins are correctly positioned and that the strap sits flush without twisting.

Aftermarket straps specifically engineered for the 15mm lug width are available in the market. Specialised suppliers such as Milano Straps offer curated selections in various materials (alligator, calf, NATO, rubber) with customisation options in dimensions, colours, and details such as embroidered initials and stitching thread. It is essential to always verify that the strap is explicitly labelled for 15mm to avoid incompatibility.

The lifespan of a leather strap depends on the chosen material, frequency of use, and maintenance practices. Under normal conditions, quality alligator can last 3–5 years before requiring replacement. Calf leather with vegetable tanning, if maintained with regular care (treatment with appropriate products every 6–12 months), can extend lifespan to 5–7 years. The standard warranty offered by specialised artisans is typically 18 months. Avoid prolonged exposure to humidity and direct sunlight to preserve leather integrity.