Strap for Speedmaster Chronoscope Master Chronometer Stainless Steel / Silver / Alligator

The lug width is 21 millimetres. This width is specific to this model and corresponds to the proportion of the 43 mm case. Do not use 20 mm or 22 mm straps: they will not fit the case correctly. Verify the measurement by placing a ruler between the two lugs on the case.

The recommendation depends on usage. Alligator offers chromatic dynamism and aesthetic nobility, ideal for occasional wear. Vegetable-tanned calf leather represents the compromise between everyday elegance and durability, developing natural patina over time. For intense sports contexts, an embroidered NATO or FKM rubber guarantees practicality without compromising the chronograph's image.

The Speedmaster Chronoscope is fitted with standard spring bars. Proceed as follows: 1) Hold the watch lug (the side of the strap attachment) with one hand. 2) Use a spring bar tool to depress the pin from below, creating space. 3) Slide the strap out of the hole. 4) Repeat on the other side. 5) Position the new strap by aligning it with the holes and reinsert the pins. Performing the operation in well-lit spaces reduces the risk of losing the pins.

Any strap constructed with a 21 mm lug width is compatible. MilanoStraps offers dedicated collections for this width, in alligator, calf, shell cordovan and NATO, all available online with fast shipping. The Casati Milano atelier also allows personal choice of leather and customization (initials, thread colour, tailored measurements) through appointment service.

Durability depends on the material and usage. A vegetable-tanned calf leather subjected to daily wear (12–14 hours per day) maintains functionality for 18–24 months before needing replacement. Shell cordovan resists up to 30 months. Alligator, due to the nature of its fibres, can extend to 24–28 months. The 18-month warranty covers manufacturing defects; natural deterioration is processual and valorial (patina).