Developer Giulio Zompetti showed off an unreleased prototype of Apple's first watch. The sample has survived almost
The developer wrote that this is a 2014 prototype.This first-generation Apple Watch has a different sensor layout for heart rate monitoring. The prototype only has two holes for LEDs and photodiodes. As a result, there were four of them in the final version of the Apple Watch. In addition, the published watch has one speaker cutout.