Replace your strap
Smartlet replaces your mechanical watch strap via the standard spring-bar system. Classic, Shadow, or Titanium. No tools required.
The Apple Watch runs the screen, the notifications and the apps. The Whoop runs silently in the background, reading sleep, recovery and strain.
People who want both usually wear two bands and live with two tan lines. Smartlet carries both on one wrist, the Apple Watch outer, the Whoop inner, each still reading your skin.
Smartlet replaces your mechanical watch strap via the standard spring-bar system. Classic, Shadow, or Titanium. No tools required.

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