Strap for Seamaster 120M Automatic 36.25 Stainless Steel / White

The Seamaster 120M 2501.21.00 has a lug width of 18 millimetres. This dimension is specific to the model and ensures proper proportion between the 36.25 mm case and the wrist. Verify it by measuring perpendicularly between the two lugs with a digital calliper, excluding any decorative plating.

Alligator is the most natural choice for this model: its rectangular tile pattern reflects the rigid geometry of the case. Alternatively, vegetable-tanned shell cordovan is excellent for those who desire leather that develops character over time. For summer, textile polyamide NATO straps maintain the sport-aquatic identity of the model.

Use a dedicated spring bar tool: insert the flat tip into the lateral spaces beneath the lug to compress the small springs. The pin will slide out. Repeat on the other side. Position the new strap by aligning it perfectly with the lugs and reinsert the pins until they click. Verify that the strap is secure before wearing the watch.

Yes, absolutely. Any strap with an 18 millimetre lug width is compatible. Artisanal quality straps offer superior aesthetic and durability advantages compared to OEM straps: you can choose premium materials such as alligator, shell cordovan or calf leather, customise the colour and even add initials.

A premium leather strap—alligator or shell cordovan—typically lasts 4-6 years with regular use and maintenance. Longevity depends on frequency of use, water exposure and care: avoid prolonged water contact, clean regularly with a soft cloth and occasionally apply a dedicated conditioner. Artisanal vegetable-tanned leather straps tend to age more elegantly than industrially produced straps.