The Zenith 4003 watch movement, introduced in 1958, features an automatic winding mechanism with a ball-bearing rotor. Notably, the rotor screw removal results in the balls falling out as there is no cage to retain them. It also incorporates a detached manual wind system and a ratchet on the dial side, along with a crown mechanism featuring a rocker bar. The Zenith 4003 movement includes functions such as automatic winding, sweep seconds, and a date display.