Omega
Speedmaster Moonwatch 311.90.42.30.01.001 (aka: 31190423001001)— lug 20mm

The lug width of the Omega Speedmaster Moonwatch 311.90.42.30.01.001 is precisely 20mm. This dimension must be measured between the two lugs of the case, excluding the lateral curves. A 19mm strap will leave empty spaces with lateral movement, while 21mm will force the lugs compromising the case integrity.

For the platinum Moonwatch we recommend alligator with fine grain for visual contrast, vegetable-tanned calf dyed navy blue for daily versatility, or shell cordovan for those wishing to acquire historical patina over time. The choice depends on the intended use: pure formal, dressy-casual, or competition.

Strap replacement requires the use of a spring bar tool. Position the Moonwatch on a stable surface, locate the tiny spring bar connecting the strap to the lugs, gently push it with the tool until release, then extract the spring bar. Repeat on the other side. Install the new strap by reversing the process.

No. Although many Omega watches use the 20mm lug width, the specific geometry of the Moonwatch lugs (curves, depth, distance) makes it advisable to use straps tested specifically for the 311.90.42.30.01.001. Generic 20mm straps may not fit correctly.

The lifespan of a leather strap varies based on material: French alligator lasts 3-5 years with daily wear; vegetable-tanned calf 2-3 years; shell cordovan 5-7 years thanks to fiber density. Frequency of wear, contact with sweat, water and sunlight accelerate aging. Casati Milano guarantees its artisanal straps for 18 months.