Technical Archive

Doxa
SUB 300 821.10.241.10— lug 20mm

Doxa SUB 300 821.10.241.10: 20mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

SUB 300 Aquamarine / Bracelet

Artisanal Note

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

Technical Specifications

Doxa 821.10.241.10
Lug Width
20 mm

The essential strap measurement.

Browse 20mm straps →
Reference

821.10.241.10

Movement

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

The Heritage

The SUB 300 was launched by Doxa in the 1960s as a professional dive watch. It features the automatic ETA 2824-2 caliber with hour, minute, second and date indication. The lugs measure 20mm in width.

FAQ

What is the exact lug width of the Doxa SUB 300 821.10.241.10?

The lug width of the Doxa SUB 300 821.10.241.10 is 20 mm. This measurement represents the space between the two lugs where the strap is inserted. It is essential to verify this dimension before ordering a strap, as even minor measurement errors would make the accessory incompatible with your watch.

What strap is recommended for the Doxa SUB 300 821.10.241.10?

The Doxa SUB 300 821.10.241.10 pairs beautifully with vegetable-tanned alligator leather straps, which develop natural patina over time. For actual diving use, a robust fabric NATO or vulcanised rubber strap ensures excellent water resistance and quick drying. Shell cordovan straps offer luxury and durability, ideal for formal contexts. Choose based on your primary use case.

How do you change the strap on the Doxa SUB 300 821.10.241.10?

Strap replacement is performed using the spring bars: small metal levers that protrude from the case. Position the watch on a soft surface, then use a spring bar tool to gently compress the lug and slide the strap outward. Perform this operation on both sides, then slide the new strap through the case attachments until the spring bars click into place. Avoid forcing to prevent damage to the lugs.

Is a high-quality aftermarket strap compatible with the Doxa SUB 300 821.10.241.10?

Absolutely yes. Any strap with a 20 mm lug width is compatible with the SUB 300 821.10.241.10, provided it is manufactured to adequate construction standards. Artisanal high-quality straps often exceed original equipment straps in materials and finishing. Always verify the lug width before ordering and ensure that the shoulder pieces fit perfectly against the case.

What is the average lifespan of a leather strap for the Doxa SUB 300 821.10.241.10?

A high-quality artisanal leather strap lasts an average of 3 to 5 years with daily wear. This period extends to 5-7 years if the strap is worn occasionally. Longevity depends on the tanning method used: vegetable-tanned leather ages better than synthetic tannins, developing patina and character over time. Regular maintenance—cleaning with a damp cloth and occasional conditioning—significantly extends the strap's life.