Strap for Seamaster Diver 300M Master Co-Axial 44 Chronograph Stainless Steel / Blue / Bracelet

The lug width is 21mm. This width is specific to this model and is measured between the two lugs of the case. Any compatible strap must respect this exact dimension for secure and aesthetically correct mounting.

There is no universal choice. For formal elegance, alligator or cordovan leather offer sophistication; to preserve the diving heritage, Tropic rubber or NATO straps are authentic choices; vegetable-tanned calfskin balances tradition and versatility. The choice depends on how you intend to wear the watch and your typical wardrobe.

Use a spring bar tool to gently push the spring bar inward while removing the strap from the case. Insert the new strap by aligning the holes with the spring bars, then snap the spring bar into position. If you are uncertain, consult a professional watchmaker to avoid damage to the case.

Artisanal aftermarket straps such as those from Casati Milano offer selected materials, customization, and often comparable build quality at lower costs than official Omega straps. What matters is respecting the 21mm lug width and verifying compatibility with the spring bars of your case.

A quality strap with vegetable tanning typically lasts 3-5 years with daily wear, varying based on frequency of use, sun exposure, and proper maintenance. A rubber or NATO strap has greater longevity (7-10 years), while shell cordovan, if maintained, can last over a decade while developing a precious patina.