Strap for SUB 300 Carbon Aquamarine

The lug width of the Doxa SUB 300 822.70.241.20 is exactly 20 mm. This measurement defines compatibility with aftermarket straps. To measure correctly, position a digital calliper between the inner right and inner left points where the strap inserts into the case lugs. Verifying this dimension before purchase is essential to avoid incompatibility issues.

The best strap depends on intended use. For formal and professional contexts, a brown alligator strap in vegetable tanning offers elegance and develops patina over time. For diving and marine environments, vulcanised rubber (FKM) is the specialist choice: waterproof, resistant to sea salt corrosion, requires minimal maintenance. NATO fabric straps in cordura offer tactical practicality and rapid changeovers. All must feature a 20 mm lug width for compatibility.

Changing the strap requires precision. Position the watch on a soft surface. Locate the articulation pins (metal bars) connecting the strap to the lugs. Using a dedicated tool (spring bar tool or watchmaker's pin), press the pin to release one side of the strap, then extract it. Repeat on the other side. Insert the new 20 mm strap by clicking the pins into the lug holes. Verify secure positioning before wearing the watch.

Yes, aftermarket straps with 20 mm lug width are widely available. MilanoStraps.it offers a complete collection: artisanal leather (calf, alligator, shell cordovan), NATO straps in technical fabrics and vulcanised rubber straps. All are engineered for compatibility with the Doxa SUB 300 and other 20 mm dive watch references. Artisanal quality ensures precise finishing and longevity superior to OEM straps.

Leather strap lifespan depends on material and usage patterns. A quality artisanal alligator strap in vegetable tanning lasts 5–8 years with regular use and basic maintenance (annual conditioning with neutral wax, protection from salt water with hydrophobic spray). Aniline calf, being softer, may last 4–6 years. Vulcanised rubber, if rinsed properly after diving, exceeds 10 years. The natural patina that develops over time is considered a desirable characteristic, not a flaw.