Strap for Real Moon Joure

The lug width (or ansa width) of the Christiaan van der Klaauw CKRJ3355 is 20mm. This measurement refers to the internal space between the case lugs and is essential for identifying compatible straps. You can measure it accurately using a digital calliper on the inner diameter of the lug holes, excluding the lug body itself. Precise measurement ensures compatibility without forcing and preserves case integrity.

For the CKRJ3355, we recommend high-quality alligator straps (for formal use and visible ageing), vegetable-tanned calf leather (for natural patina development), or heavyweight cotton NATO (for everyday practicality). Shell cordovan represents the premium option for legendary durability. Your choice depends on intended use and aesthetic preferences: the astronomical dial deserves a strap that reflects the Dutch manufacture's constructive precision.

To change the strap, remove the case lugs (typically using a spring bar tool). Position the watch with the lug facing you, gently insert the spring bar tool into the lateral hole of the lug to compress the internal spring, then extract the lug from the case. Repeat on the other side. Insert the new lugs into the new strap, compress the spring, and position the lug into the case holes until you hear a click. Verify that the lug is completely locked before wearing the watch.

All straps with 20mm lug width are compatible with the CKRJ3355. We recommend artisanal, quality straps made from vegetable-tanned leather, alligator, shell cordovan, or heavyweight cotton NATO. Avoid industrially-produced straps with non-standard lugs: the CKRJ3355's constructive quality deserves equally solid straps. On MilanoStraps you'll find a curated selection of 20mm compatible straps, ready for dispatch and customisable according to your colour preferences.

A high-quality leather strap (alligator, calf, shell cordovan) worn daily typically lasts 3–5 years, with the possibility of replacing the lugs to extend useful life. Vegetable-tanned leather ages elegantly, developing characteristic patina, whilst alligator maintains superior elasticity over time. Shell cordovan can last over 15 years with proper maintenance. Lifespan depends on use conditions, ambient humidity, and cleaning frequency. A NATO or rubber strap offers comparable durability but superior environmental resistance in damp or professional contexts.