Strap for Speedmaster Professional Moonwatch SpeedyMoon

The lug width of the ST 345.0809 is 20 millimetres. This width is standard for the Speedmaster Professional family and is measured internally between the lug shoulders, which is the space where the strap anchors through the spring bars. To verify compatibility, remove your current strap and measure the distance between the two lugs: it must be exactly 20 millimetres to ensure smooth insertion and operational convenience.

The choice depends on your use and aesthetic preferences. Alligator leather, particularly in vegetable tanning, offers maximum sophistication and develops a fascinating patina over time. Vegetable-tanned calf leather provides softness and formal versatility. Shell cordovan allows for spectacular patina development and superior durability. For daily use and versatility, high-density polyamide NATO is robust and practical. Natural rubber remains ideal for sports contexts. We recommend honey brown or polished black alligator to maintain the elegance of the chronograph.

Remove the watch from your wrist. Locate the spring bars that pass through the lugs: these small metal cylinders hold the strap in place. Using a specialised tool (a spring bar tool or small cross-head screwdriver), apply pressure to push the spring bar toward the opposite side until it detaches completely. Repeat for both spring bars. Then insert the new 20mm strap by aligning the holes and reinsert the spring bars with gentle pressure until firmly positioned. Avoid excessive force to preserve the stainless steel lugs.

Yes, any strap with a lug width of 20 millimetres is compatible with the ST 345.0809. Quality aftermarket straps made from alligator, calf, shell cordovan or synthetic materials offer endless possibilities for aesthetic and functional customisation. The important thing is to verify that the width is exactly 20 millimetres and that the strap is made to high construction standards to preserve the value and aesthetics of the Moonwatch chronograph.

Longevity depends on the type of leather, the tanning method and your usage. An alligator or shell cordovan leather in vegetable tanning, with regular care, lasts on average 3-5 years of daily use, while developing a fascinating patina in the meantime. Vegetable-tanned calf maintains optimal condition for 2-4 years. A synthetic NATO or natural rubber can exceed 5-7 years without visible degradation. Prolonged exposure to humidity, sweat and UV rays accelerates the natural ageing of the leather. Periodic maintenance (gentle cleaning, conditioning with specific products) significantly extends the overall lifespan of the strap.