Longines
HydroConquest L3.782.3.96.9— lug 21mm

The lug width is 21mm. Measured as the internal space between the two lugs (eyelets) from wall to wall. This specification is essential for selecting a compatible strap: 20mm straps will seat with excessive play, while 22mm straps will not fit. It is a non-standard width for civilian diving watches of 43mm diameter, requiring dedicated solutions.

African alligator with vegetable tanning is the natural choice for a diving instrument: it absorbs moisture, maintains flexibility after saltwater immersion, and develops patina naturally over time. Grained calf is a versatile alternative for daily urban and occasional underwater wear. Vulcanised rubber remains the most logical solution if you wear the watch in the sea: immediate drainage, rapid drying, UV durability.

The strap is secured via eyelets on the case lugs. Use a spring bar tool or fine pointed instrument: insert the pin into the eyelet hole with lateral pressure to compress the internal spring, remove the old strap, insert the new one ensuring the spring bar is correctly positioned. Avoid excessive force that could scratch the case.

An aftermarket strap must have precisely 21mm lug width to seat without excessive play in the Longines eyelets. Generic or standard aftermarket straps (20mm or 22mm) are not compatible. Custom artisanal solutions ensure perfect fit and adjustable length for various wrist sizes.

A quality vegetable-tanned alligator strap lasts typically 3–5 years with daily wear, developing visible patina over time. Durability depends on: frequency of wear, exposure to saltwater/chlorine, leather maintenance (periodic cleaning, immediate drying after swimming). Calf straps have similar lifespan but require greater humidity attention. Casati Milano artisanal guarantee is 18 months for manufacturing defects.