Tudor Monarch & Fitbit Air on the same wrist

Tudor Monarch & Fitbit Air on the same wrist

Despite its integrated look, the Tudor Monarch uses standard spring bars in 20mm lugs, so it fits Smartlet One on 20mm watch adapters. Fitbit Air support is coming soon, with a dedicated adapter. Once available, the Monarch sits on top of the wrist and the Air underneath, against the skin.
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Compatibility guide

Tudor Monarch & Fitbit Air on the same wrist

Tudor Monarch + Fitbit Air
Despite its integrated look, the Tudor Monarch uses standard spring bars in 20mm lugs, so it fits Smartlet One on 20mm watch adapters. Fitbit Air support is coming soon, with a dedicated adapter. Once available, the Monarch sits on top of the wrist and the Air underneath, against the skin.
Tudor Monarch lug width
20mm
Fitbit Air compatibility
Screenless tracker (2026)
Adapter
Dedicated Fitbit Air adapter, coming soon
Sensor position
Underneath the wrist

Why the Tudor Monarch and Fitbit Air belong to the same wrist

Is the Tudor Monarch compatible with Fitbit Air on Smartlet?

Compatible
Despite its integrated look, the Tudor Monarch uses standard spring bars in 20mm lugs, so it fits Smartlet One on 20mm watch adapters. Fitbit Air support is coming soon, with a dedicated adapter. Once available, the Monarch sits on top of the wrist and the Air underneath, against the skin.
Tudor Monarch lug width
20mm Supported
Watch adapters in the lug holes
Fitbit Air model
Screenless tracker (2026)
Dedicated Fitbit Air adapter, coming soon
Sensor position
Underneath the wrist
Against the skin
Reversible
Fully
No modification to the watch

Related compatibility guides

Model guide
Tudor Monarch
→
Brand guide
All Tudor models
→
Smartwatch guide
Fitbit Air compatibility
→

More ways to wear Smartlet

Tudor Monarch + Apple Watch
Tudor Monarch
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Rolex Submariner + Fitbit Air
Rolex Submariner
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Rolex Datejust + Fitbit Air
Rolex Datejust
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Choose your Smartlet

Step by step

Replace your strap
01

Replace your strap

The watch adapters seat in your mechanical watch's lug holes in place of the spring bars. Classic, Shadow or Titanium. The spring bar tool is in the box.

Connect your wearable
02

Connect your wearable

Your smartwatch attaches to the central part of the bracelet with its own adapter (Apple Watch, Whoop, Fitbit, Galaxy or Pixel Watch) or a pair of standard watch adapters. Zero modification to the mechanical watch.

Wear both simultaneously
03

Wear both simultaneously

Both watches sit on the same wrist. The smartwatch sits underneath, against the skin.

Questions

Frequently asked questions

  • Is the Monarch's bracelet removable for Smartlet?
    Yes. The H-link bracelet attaches with standard spring bars; the vertical lines running to the lugs are decorative engravings on the case. Smartlet One replaces the bracelet with watch adapters in place of the spring bars, and the change is fully reversible.
  • Which Monarch reference is compatible?
    The Monarch, launched in 2026, is listed in our base as one reference, M2639W1A0U-0001 with a champagne dial. It fits Smartlet One on 20mm lugs with standard spring bars.
  • How does the Fitbit Air attach?
    With a dedicated Fitbit Air adapter, coming soon, designed for the Air's attachment system. It will hold the Air underneath the wrist, against the skin.
  • Does Smartlet damage or modify my mechanical watch?
    No. The watch adapters seat in your watch's lug holes in place of the spring bars. Nothing is modified on the case, lugs or dial, and the change is fully reversible: your mechanical watch can go back on its original strap at any time.