Wear a smartwatch with your Seiko Seiko 5

Wear a smartwatch with your Seiko Seiko 5

Smartlet is compatible with the Seiko Seiko 5. Lug width: 19mm / 20mm / 22mm - natively supported with no adapter. Installation uses the standard spring-bar system. No modification to the watch required. Fully reversible in seconds.
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Seiko Seiko 5 compatibility

Wear a smartwatch with your Seiko Seiko 5

In short Smartlet is compatible with the Seiko Seiko 5. Lug width: 19mm / 20mm / 22mm - natively supported with no adapter. Installation uses the standard spring-bar system. No modification to the watch required. Fully reversible in seconds.

The Seiko 5 is the watch that proved automatic movements could reach everyone. Launched in 1963 with five principles - automatic winding, day/date display, water resistance, recessed crown at 4 o'clock, and a durable case - the 5 series has remained in continuous production for over sixty years. The current Sport line modernised the design language in 2020, adding dial colours and case proportions that the watch community received as genuinely good design. More Seiko 5s are sold annually than most Swiss brands produce in a decade.

Wear yours How it works
The problem
Choosing between health data and horological heritage every morning.
The solution
Smartlet One replaces your Seiko Seiko 5'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
Seiko Seiko 5
Lug width
19mm / 20mm / 22mm
References
11covered
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 (16)

Stealth. Switch in seconds, leave no trace.

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

Seiko Seiko 5 models supported

Covered references

11 references covered.

ReferenceMaterialDialLugSmartlet
5126-6010Stainless Steel 38mmSilver19mmCompatible
6119-6050-RallyStainless Steel 40mmBlack/Orange Rally20mmCompatible
6139-8002Stainless Steel 38mmBlue19mmCompatible
Vintage-5-Lion-1974Stainless Steel 38mmSilver19mmCompatible
7009-876AGold-Tone 38mmChampagne19mmCompatible
7009-600A-ARStainless Steel 40mmArabic Black20mmCompatible
SRPD55Stainless Steel 42mmBlack22mmCompatible
SRPD51Stainless Steel 42mmBlue22mmCompatible
SRPD53Stainless Steel 42mmPepsi22mmCompatible
SNKZ15Stainless Steel 42mmBlack/Red22mmCompatible
SNKZ17Stainless Steel 42mmBlack/Blue22mmCompatible

Seiko Seiko 5 lug widths: 19mm / 20mm / 22mm

The Seiko 5 is the watch that proved automatic movements could reach everyone. Launched in 1963 with five principles - automatic winding, day/date display, water resistance, recessed crown at 4 o'clock, and a durable case - the 5 series has remained in continuous production for over sixty years. The current Sport line modernised the design language in 2020, adding dial colours and case proportions that the watch community received as genuinely good design. More Seiko 5s are sold annually than most Swiss brands produce in a decade.
Frequently paired

Smartwatches worn with Seiko Seiko 5

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
Combination guides

Wear it both ways

Seiko Seiko 5 + Fitbit Charge
Fitbit Charge
→
Also compatible

Other brands

Other iconic models in the Smartlet compatibility library.

Submariner
Daytona
GMT-Master
Datejust
Yacht-Master
Sky-Dweller
Explorer
Seamaster 300m
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
Fifty Fathoms
Reverso
SUB 300
Spring Drive
Essence Leggera
Aquis
Divers Sixty-Five
Chronograph 1
Captain Cook
Superman Heritage
El Primero
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

  • Does Smartlet work with the Seiko 5?
    Yes. All current Seiko 5 Sport references use 19mm to 22mm lugs - natively supported by Smartlet. No adapter required.
  • Which Seiko 5 references are compatible with Smartlet?
    SRPD51, SRPD53, SRPD55 Sport series at 22mm, and older 7009 and 6119 series at 19mm and 20mm - all within Smartlet's native range.
  • Can I wear an Apple Watch with my Seiko 5?
    Yes. Smartlet attaches to the Seiko 5 via the spring-bar slots and holds your Apple Watch, Garmin, or other smartwatch on the same wrist simultaneously.
  • Where can I buy Smartlet for the Seiko 5?
    Smartlet is available at smartlet.io in Classic, Shadow, and Titanium. All finishes are compatible with Seiko 5 references at 19mm to 22mm lug widths.
  • 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.