Strap for Master Collection 40 Chronograph Calendar Stainless Steel / Black / Strap

The lug width of the Longines Master Collection L2.673.4.51.7 is 21 mm. This measurement represents the distance between the inner vertices of the two lugs on the case. To verify it correctly, use a digital calliper and measure the distance between the inner shoulders of the lugs: the result must be exactly 21 mm to ensure precise strap fitting.

The best strap for the Master Collection L2.673.4.51.7 is superior-quality alligator, preferably in dark brown or anthracite grey. Alligator provides structural rigidity appropriate to the watch's weight, elegant texture that does not compete with the dial, and durability over time. Alternatively, shell cordovan represents a refined choice for those who appreciate natural leather patination, whilst vegetable-tanned calf is ideal for those preferring a strap that moulds to the wrist, developing character over time.

Strap replacement is performed by removing the strap bars that connect the strap to the case. Position the watch on a soft, flat surface and use a strap removal tool or small flat-head screwdriver. Gently push the pin from one side until it emerges completely from the lug. Once the old strap is removed, align the new strap's holes with the lugs and reinsert the pins. Ensure the pins are fully inserted and secure before wearing the watch.

Aftermarket straps compatible with the Master Collection L2.673.4.51.7 must have a 21 mm lug width. They are available in premium materials including alligator, shell cordovan, calf leather, nubuck, ballistic canvas NATO and fluoroelastomeric rubber. MilanoStraps offers a dedicated collection of 21 mm straps customisable with leather selection, colours, individual lengths and buckle finishes. You may choose a standard buckle, a stainless steel or titanium deployant, or a traditional leather loop based on aesthetic and functional preferences.

The lifespan of a leather strap depends on the quality of the raw material, tanning method and intensity of wear. A superior-quality alligator strap, worn daily, maintains structural integrity for 3–5 years before requiring buckle replacement or minor repairs. Shell cordovan, thanks to natural fibre density, may last 5–7 years with proper maintenance (protection from excessive moisture and regular drying). Vegetable-tanned calf tends to wear more quickly (2–3 years with heavy wear), though this process generates a fascinating patina. Longevity increases significantly if the strap is not worn daily.