3 ms·

Apparently the Apple Watch does it when using the "unlock your Mac" feature. https://networkingnerd.net/2016/09/21/apple-watch-unlock-802-11ac-and-time/ https:

• theshrike79 4y ago
  It also notifies the user with a haptic and audio notification when the Watch has been used to unlock a Mac. In an open plan office it works around 2 meters away at maximum. There seems to be some kind of heuristic when it allows it too, the first login for the day requires a password or TouchID to be used, but the ones after that work via the Watch.