VM-1 display with backboard set up to read AC Hz (frequency) up to 199.9hz. Backboard has RHZ converter, 12 volt DC to DC isolated power supply, and 4 wire screw terminal connections. Powered from 12vdc (24vdc option at increased cost). You must be able to solder the appropriate jumpers as described in the instruction sheet. Includes panel mounting hardware. Optional smoked lens (bezel). Specify signal voltage range from drop down box.