Codex XBand Smart Watch Strap
Watch enthusiasts have taken to strapping a Whoop or Fitbit Air onto their off-hand just to get fitness tracking without giving up their mechanical watch, a workaround that mostly just makes both wrists look cluttered. Codex's answer, the XBand, hides the sensors inside the clasp instead, so a single strap does double duty. The clasp itself is styled after Rolex's Oysterflex, built onto a rubber strap sized the way a Patek Philippe Aquanaut band is, cut to fit rather than punched with holes. The sensor tracks heart rate, blood oxygen, stress, and sleep, routing everything to a companion app instead of a screen.

