Doxa
SUB 300 840.10.351.21— lug 20mm
Doxa SUB 300 840.10.351.21: 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 840.10.351.21The essential strap measurement.
Browse 20mm straps →840.10.351.21
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 300 840.10.351.21?
The lug width of the Doxa SUB 300 840.10.351.21 is 20mm. This measurement represents the distance between the lugs on the watch case that hold the strap in place and is essential for ensuring compatibility with aftermarket straps. When measured correctly, it allows the use of a wide range of straps without lateral play or structural misalignment.
What is the best strap material for the Doxa SUB 300 840.10.351.21?
The choice depends on the intended use: for formal occasions, an alligator strap with vegetable tanning conveys elegance whilst maintaining the model's authenticity; for daily marine use, a NATO strap in woven nylon offers robustness and quick drying; for deep diving, vulcanised FKM rubber ensures thermal stability and chemical resistance. Each material represents a conscious compromise between aesthetics and practicality.
How do you change the strap on the Doxa SUB 300 840.10.351.21?
Strap changing requires a dedicated tool (spring bar tool) to remove the elastic pins that connect the strap to the case. Position the watch on a stable surface, insert the flat tip of the tool into the access hole of the lower lug, apply gentle pressure to release the pin, then extract it. Repeat the operation on the upper lug. Insertion of the new strap follows in reverse sequence, ensuring that the pins click into position with an audible confirmation.
What aftermarket strap is compatible with the Doxa SUB 300 840.10.351.21?
Any strap with a 20mm lug width is compatible with the Doxa SUB 300. This includes leather straps (alligator, calf, shell cordovan with vegetable or chromium tanning), NATO straps in woven nylon, vulcanised FKM rubber straps and hybrid leather-rubber straps. Compatibility is guaranteed provided the lug width does not deviate from the 20mm specific to this model.
How long does a leather strap last on the Doxa SUB 300 840.10.351.21?
The lifespan of a leather strap depends on frequency of use, exposure to moisture and the construction quality of the material. An alligator or shell cordovan strap with vegetable tanning, used daily in a non-maritime environment, maintains structural integrity for 3-5 years; a chromium-tanned calf strap offers similar durability with less initial patina development. Regular exposure to seawater reduces longevity to 12-18 months, so vulcanised FKM rubber straps are recommended for frequent diving and seasonal changes to preserve the material.