HOUR METER - VERTICAL INSTALLATION - WITH ADAPTER RING FOR 60MM DIAMETER CUT-OUT - RECORDS THE RUNNING TIME OF MACHINES, VEHICLES, ETC. WHICH VIBRATE DURING OPERATION - THE AUTOMATIC MECHANISM IN THIS METER CONVERTS VIBRATIONS INTO ENERGY WHICH DRIVES THE HOUR METER AND MINUTE SWEEP HAND - IT IS SO SENSITIVE, IT IS CAPABLE OF OPERATING FROM THE SLIGHT VIBRATION OF A MOVING CAR