Strap for Modello Tre U3-AS Apollo-Soyuz Mission

The lug width of the Unimatic Modello Tre U3-AS is 22mm. This measurement is critical for strap compatibility: all accessories must have this dimension to ensure perfect fit between the watch case lugs.

Tuscan leather with vegetable tanning in a burnt brown tone represents the ideal match for the U3-AS. The natural patina that develops over time creates a fascinating contrast with the satinised steel case. Alternatively, alligator in taupe grey or shell cordovan offer elegant solutions while maintaining the tool watch authenticity of the model.

Strap change is performed via spring bars that connect the strap to the case lugs. Using a spring bar tool, compress the internal spring, extract the bar, and remove the old strap. The process requires care to avoid scratching the case: we recommend working on a soft surface and proceeding methodically.

All straps with a 22mm lug width are compatible with the U3-AS. On milanostraps.it you will find a curated selection of artisanal straps in Tuscan leather, alligator, shell cordovan, NATO, and rubber, specifically available in the 22mm size and ready for dispatch.

A quality leather strap, such as Tuscan vegetable-tanned, guarantees longevity exceeding a decade if properly maintained. Duration depends on frequency of use, climate, maintenance, and rotation with other straps. Prolonged exposure to sweat, salt water, and direct sunlight reduces service life; storage in dry, shaded conditions significantly extends durability.