Strap for Master Collection 42 Chronograph Calendar Stainless Steel / Black-Roman / Alligator

The Longines Master Collection L2.773.4.51.7 features a lug width of 21mm. This dimension is specific to this model and critical to verify before purchasing a replacement strap, as undersized or oversized lugs can damage the case over time.

For a timepiece of this constructive integrity, we recommend dark chocolate alligator, vegetable-tanned calf, or shell cordovan. These materials respect the aesthetic balance of the polished stainless steel case. Rubber straps remain the operational choice for sporting or maritime activities. Selection depends on use: formal (alligator), daily wear (calf), nautical (shell cordovan).

Strap replacement requires a specialized spring bar tool. Remove the metal spring bars from the case lugs, then disengage the old strap by gently pressing with the tool. Insert the new strap ensuring the spring bar clicks correctly into the lug slots. For professional installation, the artisans at Casati Milano offer this service.

Yes, provided it features a 21mm lug width. Artisanal straps of superior quality are fully compatible and often enhance the aesthetic experience beyond OEM solutions. Always verify the strap is crafted with noble materials (alligator, calf, shell cordovan) and features a robust clasp. The 18-month warranty from Milanese artisans protects your investment.

A quality leather strap with natural tanning (vegetable tanning) lasts 3-5 years under normal use conditions, with periodic maintenance. Alligator and shell cordovan extend lifespan to 6-8 years. Durability depends on usage intensity, climate (marine humidity accelerates wear), and care. The patina that forms over time, if maintained, is considered aesthetic appreciation in horological circles.