IWC
GST Aquatimer IW3723-01 (aka: 3723-01, IW372301)— lug 20mm

The lug width of the GST Aquatimer IW3723-01 is 20mm, measured precisely between the two spring bars that protrude from the side lugs. This measurement is standard in watchmaking and allows for the use of artisanal straps specifically designed for this width, ensuring a precise fit without lateral play.

The best strap depends on intended use and aesthetic preferences. For its professional diving character, a grey or black NATO strap reinforces the technical heritage. Cognac alligator or tobacco calf leather bring classic elegance, suitable for semi-formal occasions as well. Tropic rubber remains the choice most aligned with its diving vocation, thanks to its resistance to moisture and salt.

The strap is changed using the horizontal spring bars present on the case lugs. Using a spring bar tool (available at the Casati Milano atelier), gently push the pin to release the old strap and, while keeping the tool in position, insert the new strap into the lug until it clicks into place. The operation requires precision to avoid damaging the titanium case.

Yes, at milanostraps.it you will find 20mm compatible straps ready for shipment. These artisanal straps are customizable in size, initials, and stitching thread, and guarantee the same construction quality as IWC manufacturing. For a complete bespoke experience, the Casati Milano atelier creates custom straps with personal choice of leather.

A quality artisanal leather strap (alligator, crocodile, or calf) typically lasts 5-10 years with daily wear, thanks to natural exposure to air and light that stabilizes the leather. Casati Milano guarantees 18 months on all bespoke straps, and it is possible to request maintenance and restoration over time to extend the useful life.