Strap for Moonphase 7121 White Gold - Diamond / Grey / Tokyo 2023

The lug width of the Patek Philippe Complications Ref. 7121/200G-010 is 20 millimetres. This measurement is taken at the base of the spring bar (or pin-bar) on one of the two lugs, where the strap sits. Precise measurement is essential to ensure compatibility with an aftermarket strap.

For a white gold 18-karat timepiece with astronomical complications, American alligator on vegetable tanning is the most congruent choice: the natural grain and patina that develops over time underscore construction quality. Solid alternatives include high-grade calf leather (smoother, suited to formal contexts) and FKM rubber (for intensive wear, with a colour that subtly contrasts the white gold).

Strap replacement requires releasing the spring bar (or pin-bar, depending on attachment) on each lug. We recommend using dedicated tools (spring bar tool) to avoid scratching the white gold. If you lack experience, a specialised atelier will complete the task in minutes, ensuring precision and casing protection.

Yes, provided the strap is engineered for a 20mm lug width. Mechanical compatibility is assured by the lug width; aesthetic and construction quality, however, depends on the manufacturer. Brands specialising in fine horology offer straps that respect the finishing standards (undercut, thickness, leather) expected on Patek Philippe timepieces.

A hand-made alligator or premium calf strap with vegetable tanning lasts approximately 3–5 years with daily use and ordinary maintenance (limited exposure to water, humidity and direct heat). Patina and controlled wear are signs of natural ageing; if the strap deteriorates prematurely, replacement may be requested if covered by a manufacturing warranty (for example: Casati Milano's 18-month warranty).