Strap for Senator Perpetual Calendar Stainless Steel / Black / Alligator / Folding

The Glashütte Original Senator 100-02-25-12-50 features a lug width of 20mm. This measurement is taken between the two metal lugs protruding from the case at 12 and 6 o'clock. The correct tolerance ranges between 19.8 and 20.2mm to ensure precise fitment and zero movement within the buckle barrel.

For the Senator 100-02-25-12-50, straps in Mississippi alligator black, vegetable-tanned calf, polyamide NATO, or FKM rubber are all recommended, each with 20mm lug width. Black alligator is the canonical choice for formal contexts, while vegetable-tanned calf is ideal for those seeking a patina that evolves over time. FKM rubber ensures absolute water resistance whilst maintaining aesthetic dignity.

Strap replacement requires a spring bar tool. Position the forked end beneath the metal lug shoulder at 12 o'clock, apply gentle downward pressure until the internal spring releases, extract the pin, remove the old strap, and proceed with mounting the new one. Fitment tolerance must be verified after insertion: the strap should adhere without play.

Yes, provided the aftermarket strap is constructed with a 20mm lug width and measurement tolerances no greater than ±0.3mm. Milano Straps' artisanal straps guarantee this precision through hand-finished lug shoulders. Straps in alligator, vegetable-tanned calf, NATO, and FKM rubber are all compatible with reference 100-02-25-12-50.

Leather strap longevity depends on material, usage frequency, and environmental exposure. Premium-grade alligator with adequate tanning lasts 4–6 years in daily use; vegetable-tanned calf reaches 3–5 years. Exposure to perspiration, salt water, and UV rays accelerates ageing. Periodic rotation between two straps extends the overall lifespan of both.