Technical Archive

Doxa
SUB 300 821.10.101.20— lug 20mm

Doxa SUB 300 821.10.101.20: 20mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

SUB 300 Sharkhunter

Artisanal Note

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

Technical Specifications

Doxa 821.10.101.20
Lug Width
20 mm

The essential strap measurement.

Browse 20mm straps →
Reference

821.10.101.20

Movement

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

The Heritage

The Doxa SUB 300 821.10.101.20 is a professional dive watch with a 42.50 mm stainless steel 316L case and 20 mm lug width. It features an ETA Calibre 2824-2 movement certified chronometer with 28,800 oscillations per minute and 42-hour power reserve. The watch displays hours, minutes, seconds, and date on a radioactive orange dial protected by a domed sapphire crystal with anti-reflective coating. The unidirectional bezel and screw-down crown are essential for diving operations.

FAQ

What is the lug width of the Doxa SUB 300 821.10.101.20?

The lug width of the Doxa SUB 300 821.10.101.20 is 20 mm. This dimension is standardised for the model and has been engineered to maintain correct proportions on a 42.50 mm case diameter. Always measure the linear distance between the two lug pins on your watch before ordering a strap for compatibility confirmation.

Which strap material is best suited to the Doxa SUB 300 821.10.101.20?

Selection depends on intended use: alligator or vegetable-tanned calf for formal occasions and recreational diving; robust polyamide NATO for versatility and quick-change capability; FKM (Viton) rubber for frequent diving and saltwater resistance. All three materials are compatible with the 20 mm lug width.

How do I change the strap on the Doxa SUB 300 821.10.101.20?

Position the watch on a soft pad. Locate the lug pins on both sides. Use a spring bar tool to gently push the pin towards the case centre, creating clearance to extract the old strap. Insert the new strap into the spring mechanism, then allow the pin to snap into place. Verify both pins are correctly seated before wearing.

Are aftermarket straps compatible with the Doxa SUB 300 821.10.101.20?

Yes, provided they feature a 20 mm lug width. However, some historical manufacturers produced variants with 19 mm lugs for alternate Doxa models. Always verify technical specifications before purchasing an aftermarket strap. Artisanal-quality straps, such as those offered by Milano Straps, are engineered and tested to guarantee perfect compatibility.

What is the expected lifespan of a leather strap on the Doxa SUB 300 821.10.101.20?

A vegetable-tanned leather strap, with regular maintenance (damp cloth cleaning, air drying, occasional conditioning with dedicated balms), lasts 3–5 years with daily wear. Frequent saltwater exposure significantly reduces this duration. On a dive watch, it is advisable to own two straps: one leather for formal occasions and one NATO or rubber for diving.