Strap for Seamaster Aqua Terra 150M Co-Axial 43 Annual Calendar Red Gold / Grey

The lug width is 21 millimetres. It is measured from the inner edge of one lug to the inner edge of the other. This dimension is invariable across all examples of this reference and determines compatibility with aftermarket straps.

For the red gold 43mm, natural alligator in Cognac or Dark Brown tones is the most coherent choice from both an aesthetic and tactile perspective. Vegetable-tanned calf or shell cordovan also offer superior patina and longevity. For more sporty uses, a Tropic or FKM rubber in black or brown ensures grip and moisture resistance.

The change is effected by removing the spring bars that connect the strap to the case. Use a spring bar tool to compress the inner pin and completely extract both the pin and the old strap. Insert the new strap by aligning it to the lugs and reinsert the pin, verifying that it is fully locked. The procedure requires care to avoid scratching the red gold case.

Yes, any strap with a 21mm lug width is compatible with the 231.53.43.22.06.003 (23153432206003 is the same reference in alternative notation). Custom quality straps, such as those made by Casati Milano, are specifically designed to fit this dimension without lateral play.

A quality natural leather strap typically lasts 3-5 years with regular use, provided conscious maintenance: avoid prolonged exposure to moisture, protect from direct heat sources and subject it to periodic conditioning with natural waxes. Shell cordovan and vegetable alligator, thanks to their density and composition, tend to last longer. An FKM rubber strap offers superior durability but less aesthetic versatility.