Technical Archive

Doxa
SUB 300 840.10.351.10— lug 20mm

Doxa SUB 300 840.10.351.10: 20mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

SUB 300T Professional / Bracelet

Artisanal Note

"This model requires a precise 20mm lug width to preserve the original sartorial balance."

Technical Specifications

Doxa 840.10.351.10
Lug Width
20 mm

The essential strap measurement.

Browse 20mm straps →
Reference

840.10.351.10

Movement

ETA caliber 2824-2 Hours, Minutes, Seconds | Date

The Heritage

The Doxa SUB 300 features the automatic ETA 2824-2 caliber with indication of hours, minutes, seconds and date. The watch has 20mm lugs and maintains the technical characteristics of the SUB collection oriented to diving. The ETA 2824-2 movement offers a standard power reserve for this type of dive watch.

FAQ

What is the lug width of the Doxa SUB 300 840.10.351.10?

The lug width for the Doxa SUB 300 840.10.351.10 is 20 mm. This dimension is specific to this model and not interchangeable with the 22 mm lugs found on later-generation Doxa watches. Always verify the exact width between the lug holes using a digital calliper before ordering a replacement strap.

What strap is recommended for the Doxa SUB 300?

For the SUB 300, straps in dark brown or burgundy alligator are recommended, creating chromatic dialogue with the black dial. Vegetable-tanned Italian calf leather develops noble patina over time and is acceptable for daily wear. For frequent diving use, FKM or EPDM rubber remains stable in salt water. Fabric NATO straps serve as a temporary solution during intensive diving periods.

How do you change the strap on a Doxa watch?

Position the watch on a dedicated support pad with the dial facing downward. Use a spring bar tool to gently depress the internal spring pin of each lug. Remove the worn strap, then align the new strap ends with the lug holes. Verify that the pin engages with a perceptible double-click when fully seated.

Is an aftermarket strap compatible with the SUB 300 840.10.351.10?

Yes, any strap with a 20 mm lug width is compatible with the SUB 300 840.10.351.10. Artisanal straps featuring vegetable tanning, alligator, or rubber from specialist manufacturers maintain identical attachment specifications. Confirm the strap lacks a keeper loop (passant), as the open lugs of the SUB 300 do not accommodate this structural element.

How long does a leather strap last on a Doxa case?

A quality leather strap (vegetable-tanned calf or alligator) maintains structural integrity for 3-5 years under moderate use conditions, with controlled ambient humidity and seasonal perspiration. Vegetable-tanned leather develops visible patina after 6-12 months. Wear accelerates if exposed to frequent fresh water or prolonged submersion; salt water degrades the material within 2-3 months without protective treatment. Rotating with rubber straps during intensive diving periods is recommended.