Doxa
SUB 300 840.10.361.31— lug 20mm
Doxa SUB 300 840.10.361.31: 20mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.
Artisanal Note
"This model requires a precise 20mm lug width to preserve the original sartorial balance."
Technical Specifications
Doxa 840.10.361.31The essential strap measurement.
Browse 20mm straps →840.10.361.31
ETA caliber 2824-2 Hours, Minutes, Seconds | Date
The Heritage
Compatible Straps
Selected for the 20mm lug width of the SUB 300
FAQ
What is the lug width of the Doxa SUB 300 840.10.361.31?
The Doxa SUB 300 840.10.361.31 features a precise lug width of 20 millimetres. This dimension is specific to the model and corresponds to the width between the lugs (the metal pins that support the strap). Measured from inside to inside, it ensures that only 20mm straps mount correctly without slack or jamming in the attachments.
Which strap is most recommended for the Doxa SUB 300?
For the Doxa SUB 300, we recommend straps in alligator or vegetable-tanned calf leather if you seek narrative elegance with natural moisture resistance. If you prioritise extreme practicality for aquatic environments, a NATO in woven nylon offers zero maintenance and rapid drying. For aesthetic-functional balance, a rubber strap in black or dark blue maintains technical language without grip compromise. Avoid delicate leathers: the watch is vocationally designed to face marine environments.
How do I change the strap on my Doxa SUB 300 840.10.361.31?
Strap change is a manual operation requiring no specialist tools. Locate the two metal pins connecting the strap to the case lugs. With care, gently lever outward to extract the first pin: it will slide out horizontally. Repeat on the second pin. The strap now separates from the case. Insert the new 20mm strap by aligning the holes with the pins, then reinsert the pins by pushing until locked. Verify the strap is secure before wearing the watch.
Can I fit an aftermarket strap on this model?
Yes, any strap with a 20mm lug width is compatible. However, only straps dimensioned exactly 20mm guarantee secure mounting and visual proportions coherent with the 42.50mm case. Avoid universal undersized straps (18mm) which slip, or oversized (22mm) which do not enter the lugs. All compatible straps on Milano Straps are verified against this specification.
How long does a leather strap last on a diving watch?
Durability depends on usage intensity and environment. A vegetable-tanned leather strap with moderate humidity exposure can last 3–5 years before replacement. If exposed frequently to salt water or chlorine, lifespan reduces to 18–24 months. For intensive aquatic-only use, we recommend rubber or NATO. Each strap develops natural patina over time: this is character, not deterioration. Regular maintenance (drying after water exposure) significantly extends useful life.