Christiaan van der Klaauw · Astronomical Masterpieces

Strap for Real Moon Joure

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter40 mm
ReferenceCKRJ3304
FamilyAstronomical Masterpieces
MovementChristiaan van der Klaauw caliber CVDK7382 Hours, Minutes | Date, Month | Moonphase
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Astronomical Masterpieces CKRJ3304

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Astronomical Masterpieces CKRJ3304, seen from the bench

The Christiaan van der Klaauw Astronomical Masterpieces reference CKRJ3304 features astronomical functions with hour, minute, date, month and moon phase indications. It mounts the in-house developed caliber CVDK7382. The watch is equipped with 20mm lugs for the strap.

Frequently asked questions

What is the lug width of the Christiaan van der Klaauw Astronomical Masterpieces CKRJ3304?

The lug width of the CKRJ3304 is precisely 20mm. This measurement represents the distance between the two metal attachment points on the case where the strap lugs are fitted. It is essential to select straps specifically dimensioned at 20mm to ensure aesthetic stability and prevent unwanted lateral movement.

What is the best strap for the Christiaan van der Klaauw CKRJ3304?

The ideal strap depends on your intended use. For formal occasions, we recommend dark brown alligator or burgundy shell cordovan, which enhance the case's satiny finish and the quadrant's astronomical complexity. For daily wear, vegetable-tanned calf in cognac tones offers evolving patina and comfort. For variable environments, satin black rubber ensures durability and maintenance simplicity without sacrificing elegance.

How do you change the strap on a Christiaan van der Klaauw CKRJ3304?

Strap replacement on the CKRJ3304 is accomplished by removing the metal lugs from their anchor points on the case. Using a small tool (spring bar tool or equivalent), gently release the small pins that secure the lugs, allowing the old strap to slide away and the new one to attach at the same points. This operation requires delicacy given the case's complexity. If inexperienced, we recommend assistance from Casati Milano or a specialised centre.

Can I purchase an aftermarket strap compatible with the CKRJ3304?

Yes, absolutely. Milanostraps.it offers a complete selection of artisanal 20mm straps compatible with the CKRJ3304: leather (alligator, calf, shell cordovan), NATO, and technical rubber. All straps are produced to European artisanal standards and are ready to ship. Aftermarket selection allows you to fully personalise your watch's aesthetics while maintaining dimensional compatibility certification.

How long does a leather strap last on a Christiaan van der Klaauw CKRJ3304?

A quality leather strap (alligator, calf, shell cordovan) worn daily typically lasts 3-5 years, with variation depending on climate, frequency of use, and maintenance. Vegetable tanning develops a natural protective patina that extends material life. Ageing is not a defect but aesthetic evolution: texture deepens, colour intensifies. Periodic strap replacement is ordinary maintenance for a luxury watch and allows complete aesthetic renewal without modifying the case.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only