Strap for Seamaster Diver 300M Co-Axial 41 Stainless Steel / Black / Bracelet / Ceramic / SASR

The lug width of the Seamaster Diver 300M is 20mm. This measurement should be taken by positioning a caliper between the inner attachments of the case. All compatible straps must respect this measurement with a maximum tolerance of ±0.5mm to ensure a correct and durable fit.

The choice depends on use: for refined daily wear, dark brown alligator with vegetable tanning and sand-colored stitching is ideal; for technical diving, neoprene or vulcanized rubber are mandatory; for versatility, medium brown shell cordovan offers superior durability and lightness. All materials require a brushed steel deployment clasp for stylistic coherence.

Remove the original strap using a spring bar tool: insert the tip into the lateral notch of the upper attachment, press gently to retract the internal spring and extract the pin. Repeat for both attachments. Insert the new strap by aligning the holes with the attachments, reinsert the pins and verify that they are locked correctly without movement.

Any strap with a 20mm lug width is compatible, provided it is made by certified manufacturers. We recommend artisanal straps in vegetable-tanned leather, technical neoprene or superior quality vulcanized rubber. Always verify that the strap is equipped with lugs suitable to protect the case attachments during insertion.

A quality leather strap, made from alligator or shell cordovan with vegetable tanning, lasts an average of 3-5 years with daily use and regular maintenance. Prolonged exposure to humidity and salt water shortens its lifespan; neoprene, by contrast, resists 5-7 years even with frequent diving conditions. The Casati Milano artisanal guarantee covers 18 months.