One of the enduring mysteries in the Zenith production is the following clock It is strongly suspected to be an Italian clock of about WW2 vintage as it is double-branded Cairelli. Cairelli were a Roman jewelry firm that supplied watches to the Italian military (no connection to the Cairelli of today that is a brand-name resurrection which makes a line of wannabe military diver watches). This particular model is widely rumored to be related to naval aviation. The sides and back are not finished, as if it were meant to be mounted in an instrument panel. The green and red blocks (italian national colors, not coincidentally I suspect) are individually removable. But no one knows exactly how it is meant to work. Anyone have any guesses?