Wear a smartwatch with your Doxa SUB 300

Wear a smartwatch with your Doxa SUB 300

Smartlet is compatible with the Doxa SUB 300. All steel references use 20mm lugs, natively supported with no adapter. Installation uses the standard spring-bar system - no modification to the watch, fully reversible in seconds.
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Doxa SUB 300 compatibility

Wear a smartwatch with your Doxa SUB 300

In short Smartlet is compatible with the Doxa SUB 300. All steel references use 20mm lugs, natively supported with no adapter. Installation uses the standard spring-bar system - no modification to the watch, fully reversible in seconds.

Smartlet is compatible with the Doxa SUB 300. All steel references use 20mm lugs, natively supported with no adapter. Installation uses the standard spring-bar system - no modification to the watch, fully reversible in seconds.

Wear yours How it works
The problem
Choosing between health data and horological heritage every morning.
The solution
Smartlet One replaces your Doxa SUB 300's strap via the standard spring-bar system and positions your smartwatch on the same wrist. Both watches run simultaneously, with no modification to the watch and full reversibility in seconds.
Model
Doxa SUB 300
Lug width
20mm
References
20covered
Reversible
In seconds

Choose your edition

One mechanism. Three personalities.

Every Smartlet One includes the dedicated adapter for your wearable. Pick the finish that matches your style.

Smartlet One - Shadow - Smartlet

For the explorer

Smartlet One - Shadow

€399,00

4.9 (14)

Stealth. Switch in seconds, leave no trace.

  • Material SS316L steel, black PVD
  • Weight ~100g
  • Compatible with Rolex, Omega, Seiko + 100 more
Buy now
Compatibility

Doxa SUB 300 models supported

Covered references

20 references covered.

ReferenceMaterialDialLugSmartlet
SUB300T-RAR-MBLU-1973Steel 42.5mmMarine Blue20mmCompatible
SUB300-RAR-TOR-1974Steel 42.5mmTropic Orange19mmCompatible
SUB300-RR-1974Steel 42.5mmRuby Red19mmCompatible
SUB300T-BW-1975Steel 42.5mmBlue Wave20mmCompatible
SUB300T-CMD-1976Steel 42.5mmGrey Commando20mmCompatible
SUB200-RAR-SI-1982Steel 38mmIce Silver18mmCompatible
SUB200-RC-OR-1983Steel 38mmOrange/Black18mmCompatible
SUB118-1955-PROTStainless Steel 38mmBlack18mmCompatible
SUB1200T-OR-2009Stainless Steel 42.5mmOrange20mmCompatible
SUB1200T-YL-2010Stainless Steel 42.5mmYellow20mmCompatible
SUB1200T-SL-2010Stainless Steel 42.5mmSilver20mmCompatible
SUB1200T-BK-2010Stainless Steel 42.5mmBlack20mmCompatible
SUB1200T-BLU-2012Stainless Steel 42.5mmBlue20mmCompatible
SUB1200T-POSE-2016Stainless Steel 42.5mmBlack/Yellow20mmCompatible
SUB1200T-II-OR-2022Stainless Steel 42.5mmOrange20mmCompatible
SUB1200T-II-BK-2022Stainless Steel 42.5mmBlack20mmCompatible
SUB1200T-II-BL-2023Stainless Steel 42.5mmBlue20mmCompatible
SUB1200T-II-SL-2023Stainless Steel 42.5mmSilver20mmCompatible
SUB1500T-SL-2010Stainless Steel 45mmSilver21mmCompatible
889.10.201.10Steel 45mmBlue21mmCompatible

Doxa SUB 300 lug widths: 18mm / 19mm / 20mm / 21mm

Frequently paired

Smartwatches worn with Doxa SUB 300

The most common combinations our customers wear. Find your mechanical watch and discover the right Smartlet edition.

Apple Watch
Series 0 to Ultra 3
Whoop
5.0 / MG
Garmin Forerunner
255 to 965
Samsung Galaxy Watch
Series 4 to 7
Withings ScanWatch
Light / 2 / Nova
View all brands
27 brands covered
Also compatible

Other brands

Other iconic models in the Smartlet compatibility library.

Submariner
Daytona
GMT-Master
Datejust
Yacht-Master
Sky-Dweller
Explorer
Seamaster 300 m
Speedmaster
Planet Ocean
Constellation
De Ville
Monaco
Carrera
Formula 1
Aquaracer
Portugieser
Navitimer
Superocean
Avenger
Black Bay
Pelagos
Ranger
Luminor
Radiomir
Submersible
SKX
Prospex
Presage
Khaki Field
BR 03-92
Cinquante brasses
Reverso
Spring Drive
Essence légère
Aquis
Plongeurs soixante-cinq
Chronographe 1
Capitaine Cook
L'héritage de Superman
El Primero
Tout afficher
Monarch
Black Bay 58 GMT
View all models
Watch brand compatibility guide

Step by step

Replace your strap
01

Replace your strap

Smartlet replaces your mechanical watch strap via the standard spring-bar system. Classic, Shadow, or Titanium. No tools required.

Connect your wearable
02

Connect your wearable

Smartlet uses a dedicated adapter or native lug pins depending on your smartwatch. The connector snaps onto the Smartlet module. Zero modification to the mechanical watch.

Wear both simultaneously
03

Wear both simultaneously

Both watches sit on the same wrist. All smartwatch sensors maintain direct skin contact and operate normally.

Questions

Frequently asked questions

  • Is Smartlet compatible with the Doxa SUB 300?
    Yes. The SUB 300 uses 20mm lugs across all steel references - natively supported by Smartlet. No adapter required. The saturation valve and 300m water resistance seals are not affected.
  • Does Smartlet damage the SUB 300 water resistance?
    No. Smartlet uses the same spring-bar attachment as any strap change. The crown and case seals are completely untouched.
  • Can I use Smartlet with vintage Doxa SUB 300 references?
    Yes. Vintage references typically use 19mm or 20mm lugs - both natively supported by Smartlet. No adapter required.
  • Does Smartlet work with the Doxa SUB 300?
    Yes. The SUB 300 uses 19mm and 20mm lugs, both natively supported by Smartlet. No adapter required.
  • Does Smartlet damage or modify my mechanical watch?
    No. Smartlet replaces your standard watch strap using the existing spring-bar system. It makes no permanent modification to the watch case, lugs, or dial. The process is fully reversible in seconds. Your mechanical watch is unaffected and can be worn independently at any time by reinstalling its original strap. Smartlet is engineered to watchmaker tolerances and tested with the same care that goes into the watches it pairs with.