Strap for Speedmaster Professional Moonwatch 3861 Stainless Steel - Moonshine Gold / Silver / Alligator

The lug width is 20 millimetres. This is the distance between the two attachment points (lugs) on the case where the strap is fitted. It is measured from the inner edge of one lug to the inner edge of the other. This parameter is fixed and non-negotiable for mechanical compatibility.

There is no universal choice. Natural alligator amplifies instrumental sophistication through its distinctive geometric grain. Cordovan is the choice for those seeking maximum durability (15-20 years of continuous wear). Vegetable-tanned calf represents the ideal compromise between initial softness and evolving aesthetic patina. NATO nylon recovers the original avionic dimension. Tropic rubber is perfect for aquatic environments.

Obtain a spring bar tool (strap removal tool). Place the watch on a soft surface. Insert the thin end of the tool into the small hole beneath the lug, gently lifting the internal compression spring. The spring will retract, freeing the pin. Extract the pin and remove the old strap. Repeat on the other side. To fit the new strap, align the holes to the metal lugs, insert the pin, then compress the spring from below until it clicks into position. Never use improvised tools that could scratch the lug.

Yes. Any strap with a 20mm lug width is mechanically compatible. However, construction quality varies enormously. Hand-stitched artisanal straps in alligator, cordovan or calf guarantee superior durability and aesthetics compared to industrial straps. On milanostraps.it you will find customisable 20mm straps in material, colour and stitching thread, with the option of direct consultation at the Casati Milano atelier by appointment.

Durability depends on the material chosen. Alligator or vegetable-tanned calf lasts 5-8 years of daily wear before requiring replacement. Shell cordovan reaches 15-20 years thanks to the natural density and fibre resistance. NATO nylon exceeds 20 years. Durability varies based on wear frequency, exposure to direct sunlight, humidity and care. A strap kept dry and protected from UV light ages more slowly and with better patina compared to one subjected to constant environmental stress.