Strap for Constellation Manhattan 29 Co-Axial Master Chronometer Sedna Gold / MOP

The Omega Constellation reference 131.50.29.20.55.001 has a lug width of 18 millimetres. This is the distance between the centres of the case suspension lugs. It is a rare dimension in the aftermarket, which makes the search for a compatible strap more deliberate and specialized.

For a Constellation 131.50.29.20.55.001 in Sedna Gold, alligator remains the noblest choice: a canvas moorish brown or black enhances the rosy tone of the gold. Shell cordovan represents a fascinating alternative for those who desire a patina that evolves over time. Vegetable-tanned calf leather will instead introduce sustainability and character.

To change the strap, use a spring bar tool to gently push the small spring inside the case terminals. At the same time, remove the lug (or spring bar) from its housing. Then insert the new strap by snapping the lug into the two suspension rings. Ensure the spring bar is perfectly positioned before releasing the pressure.

Yes, you can find 18mm straps ready to ship online at specialized retailers such as Milano Straps, customizable in leather, colour, size and stitching details. However, given the rarity of this dimension, it is advisable to choose the material carefully—alligator, shell cordovan or calf—to ensure aesthetic coherence with the Sedna Gold.

A quality leather strap (alligator, shell cordovan, vegetable-tanned calf) can last 3–5 years with daily use, provided it is subjected to regular maintenance and protected from excessive moisture and perspiration. The standard warranty is 18 months. Natural aging of the leather is desirable and confers patina, not wear.