Strap for Constellation Manhattan 29 Co-Axial Master Chronometer Stainless Steel / Yellow Gold / MOP

The lug width is 18mm. This dimension represents the internal spacing of attachment between the two lugs at their base on the case. It is essential to measure correctly with a caliper in the connection zone to the case, not on the external length of the lugs themselves. All compatible straps must be specifically constructed for this width.

Mississippi alligator offers the most refined optical contrast: the fine and uniform grain of the scales amplifies the light interplay of the pearlescent dial, creating a continuous chromatic dialogue. Alternatively, vegetable-tanned calf develops a natural patina over time that imparts tactile character to the wrist, balancing the mechanical precision of the caliber 8700. NATO straps are chosen for summer rotation in casual settings.

The Omega Constellation 131.20.29.20.05.002 uses spring bar attachments: two horizontal metal bars that traverse the lugs. Use a specific tool (springbar tool) to gently lift the internal spring of one bar at a time, removing the worn strap. Insert the new strap by aligning one end first, then compress the second bar until you hear the click of closure. The operation takes approximately 2–3 minutes for those with experience; it is advisable to have it done at a jeweler if it is your first time.

All straps constructed for an 18mm lug width are compatible. On milanostraps.it you will find a complete collection of 18mm straps in alligator, calf, shell cordovan, NATO, and rubber, customizable in sizes, initials, and stitching color. Compatibility is guaranteed by ISO standardization of lug width. Avoid straps declared as 17mm or 19mm, as the manufacturing tolerance is ±0.3mm maximum.

A quality alligator or calf strap, with vegetable tanning, lasts an average of 18–36 months with daily wear, depending on exposure to moisture, sweat, and UV rays. The leather naturally softens, develops patina, but gradually loses elasticity. A shell cordovan strap, denser and more oily, can exceed 4 years. Atelier Casati Milano provides an 18-month warranty on all handcrafted straps, covering construction defects. To extend the life, remove the watch before contact with salt water and treat the strap with specific leather maintenance creams every 6 months.