Wear your Fitbit Air and your mechanical watch at the same time

Wear your Fitbit Air and your mechanical watch at the same time

Smartlet is compatible with the Google Fitbit Air via a dedicated adapter, available in pre-order with shipping in September 2026. All health sensors including heart rate, Afib alerts, SpO2 and sleep remain fully operational. The setup is fully reversible.
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Fitbit Air compatibility

Wear your Fitbit Air and your mechanical watch at the same time

In short Smartlet is compatible with the Google Fitbit Air via a dedicated adapter, available in pre-order with shipping in September 2026. All health sensors including heart rate, Afib alerts, SpO2 and sleep remain fully operational. The setup is fully reversible.

The Google Fitbit Air, released in May 2026, is a screenless wellness tracker built around a removable sensor pebble: 24/7 heart rate, Afib alerts, SpO2, skin temperature, sleep stages, seven days of battery. Smartlet positions the Fitbit Air pebble on the same wrist as your mechanical watch.

Wear yours How it works
The problem
Choosing between health data and horological heritage every morning.
The solution
Smartlet replaces your mechanical watch strap and positions the Fitbit Air pebble on the same wrist via the dedicated adapter, available in pre-order. Wear both simultaneously, without compromise to your watch or your health tracking.
Models
Screenless tracker (2026)
Lug width
Adapter included
Sensors
24/7 heart rate +
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

Fitbit Air models supported

Fitbit Air Screenless tracker (2026)
Pre-order
Smartlet is compatible with the Google Fitbit Air, the screenless wellness tracker released in May 2026. The Fitbit Air uses a proprietary pebble attachment, supported via a dedicated Smartlet adapter currently in pre-order with shipping scheduled for September 2026. All health sensors remain fully operational.
All Fitbit Air sensors remain fully operational

Smartlet positions your wearable with full skin contact maintained at all times. Health data accuracy is unaffected.

24/7 heart rateHeart rhythm with Afib alertsSpO2Skin temperatureSleep stages
Frequently paired

Mechanical watches worn with Fitbit Air

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

Rolex
Rolex Cosmograph Daytona·Rolex Datejust 41·Rolex Explorer·Rolex GMT-Master II
18.0mm / 19.0mm / 20.0mm / 21.0mm / 22.0mm / 23.0mm
Omega
Omega Aqua Terra·Omega Constellation Co-Axial·Omega De Ville Tresor·Omega Seamaster 300M
18.0mm / 19.0mm / 20.0mm / 21.0mm / 22.0mm / 23.0mm
Tudor
Tudor Black Bay 41·Tudor Pelagos 42·Tudor Ranger·Tudor Monarch
18.0mm / 19.0mm / 20.0mm / 22.0mm
TAG Heuer
TAG Heuer Aquaracer Professional 300·TAG Heuer Carrera Chronograph 42·TAG Heuer Formula 1·TAG Heuer Monaco
18.0mm / 19.0mm / 20.0mm / 21.0mm / 22.0mm
Seiko
Seiko Presage·Seiko Prospex SPB143·Seiko SKX Diver·Seiko Seiko 5
18.0mm / 19.0mm / 20.0mm / 21.0mm / 22.0mm / 23.0mm / 24.0mm
Breitling
Breitling Avenger·Breitling Navitimer B01 43·Breitling Superocean Automatic
20.0mm / 21.0mm / 22.0mm / 24.0mm
IWC
IWC Big Pilot·IWC Portugieser Automatic 40
18.0mm / 20.0mm / 21.0mm / 22.0mm
View all brands
27 brands covered
Also compatible

Other smartwatches

Smartlet works with all major smartwatches via dedicated adapters or native lug widths.

Apple Watch
Samsung Galaxy Watch
Garmin Forerunner
Polar Vantage
Google Pixel Watch
Huawei Watch GT
Fitbit Charge
Fitbit Air
Whoop
Garmin Venu
Withings ScanWatch
Coros
Suunto
Ver todo
View all
Smartwatch 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

  • Can I wear a Fitbit Air and a mechanical watch at the same time?
    Yes. Smartlet makes it possible to wear your Fitbit Air and a mechanical watch simultaneously on the same wrist. Smartlet replaces your mechanical watch strap via the standard spring-bar system and holds your Fitbit Air against the same wrist. Both watches run at the same time. All Fitbit Air health sensors maintain full skin contact and operate normally. You no longer have to choose between health data and your mechanical watch every morning.
  • Which Fitbit Air models are compatible with Smartlet?
    Smartlet is compatible with the Google Fitbit Air, released in May 2026. The Fitbit Air uses a proprietary pebble attachment system. Smartlet supports it via a dedicated adapter, available as a pre-order with shipping in September 2026. Orders placed now reserve your unit and lock in your delivery slot. Smartlet is compatible with any mechanical watch between 18mm and 24mm lug width, covering the vast majority of the market including Rolex, Omega, Tudor, TAG Heuer, Seiko, Breitling, and IWC.
  • Will Fitbit Air sensors still work when used with Smartlet?
    Yes, all sensors remain fully operational. Smartlet positions the Fitbit Air against your wrist with full skin contact maintained at all times. The following sensors continue to function normally: 24/7 heart rate, heart rhythm with afib alerts, spo2, skin temperature, sleep stages. There is no interference with the sensor array, and health data accuracy is unaffected.
  • ¿Smartlet daña o modifica mi reloj mecánico?
    No. Smartlet reemplaza tu correa de reloj estándar utilizando el sistema de pasador de resorte existente. No realiza ninguna modificación permanente en la caja, asas o esfera del reloj. El proceso es completamente reversible en segundos. Tu reloj mecánico no se ve afectado y puede usarse de forma independiente en cualquier momento reinstalando su correa original. Smartlet está diseñado con tolerancias de relojero y probado con el mismo cuidado que se dedica a los relojes con los que se empareja.