Strap for Speedmaster Broad Arrow Stainless Steel / Black / Bracelet

The lug width of the Broad Arrow 3551.50.00 is exactly 20 millimetres. This standard is specific to Omega's medium-to-large format sports instruments and determines compatibility with aftermarket straps. To verify the measurement, measure the internal distance between the integrated spring bars at the lugs of the case.

Alligator is the most versatile choice for the 3551.50.00: it combines structural robustness, moisture-absorption capability and aesthetics consistent with the Speedmaster's instrumental vocation. Vegetable-tanned calf represents the artisanal alternative, developing a natural patina over time. For intensive use and humid environments, vulcanised rubber or NATO fabric guarantee superior durability.

Use a spring bar removal tool (available online) or a small watchmaker's lever. Position yourself on the side of the case where a spring bar protrudes slightly, apply perpendicular pressure until the spring compresses, then remove the strap from the lug. Repeat on the other side. Install the new strap by reversing the process, ensuring the spring bars engage firmly.

All straps with a 20mm lug width are mechanically compatible with the 3551.50.00. The online collection of milanostraps.it offers dozens of options in alligator, calf, shell cordovan, rubber and fabric, all available in 20mm size. Always verify that the strap has adjustable spring bars if the case presents particular geometries at the lugs.

A quality leather strap on a chronograph like the 3551.50.00 typically lasts between 3 and 5 years with daily use, 5-7 years with moderate use. Durability depends on exposure to moisture, perspiration, direct sunlight and maintenance frequency. Vegetable-tanned calf straps develop an aesthetic patina over time, while alligator maintains greater structural rigidity. Casati Milano offers an 18-month warranty on bespoke straps, covering manufacturing defects.