Doxa
SUB 300 822.70.101.20— lug 20mm

The Doxa SUB 300 822.70.101.20 features a lug width of 20mm. This measurement is precise and requires exact conformance: an aftermarket strap must respect exactly 20mm width to ensure a perfect fit without lateral play. Correct measurement is achieved by placing a ruler between the two lugs of the case, beneath the spring bar, yielding 20mm.

This depends on intended use and personal preferences. For understated elegance, shell cordovan or vegetable-tanned calf leather complements the titanium case's sobriety. For daily versatility, robust dark brown calf offers extended comfort and ages beautifully. For sporting and aquatic functionality, cotton NATO or FKM rubber guarantee extreme reliability. Natural, unvarnished alligator leather adds quiet luxury without stylistic excess.

Strap replacement is straightforward: place the watch on a soft surface, locate the quick-release spring bars beneath the lugs. Using a dedicated tool (spring bar tool) or small flathead screwdriver, gently press inward to release the worn strap. Insert the new 20mm-width strap, ensuring the spring bars click securely into position. Verify no lateral play exists before wearing.

A 20mm strap is compatible with all timepieces featuring identical lug width. Before purchasing, always measure your watch's lugs using a ruler between the two lugs: if exactly 20mm, the strap will be compatible. Models from other manufacturers (Seiko, Tissot, Tudor, etc.) sharing 20mm lug width can utilise the same strap, ensuring maximum versatility.

Leather strap longevity depends on tanning method, leather grade and usage intensity. Robust vegetable-tanned calf can last 3–5 years with ordinary maintenance. Shell cordovan, denser and more resilient, may exceed 6–7 years. Factors including sun exposure, humidity, replacement frequency and buckle quality accelerate ageing. Proper care—hydration with appropriate creams and protection from heavy rain—significantly extends strap lifespan.