The Unitas 6503 watch movement features a pin-lever escapement and is equipped with an indirect minute hand friction clutch on the barrel. It has the capability to stop only the second hand while the movement continues running. Early samples of this movement may have included Palierfix combined settings instead of real shock devices. Variations in the balance cocks exist, but specific differences between the 144 and 145 versions are not known. The Unitas 6503 movement functions as a simple manual-wind chronograph with a 60-second measurement capability. It enables the start/stop of the second hand but lacks a reset feature. Additionally, it includes a sweep second hand and belongs to a period approximately around 1960.