Voltage monitor kit monitors voltages using 7 LEDs (2 red, 2 yellow, 3green) as a bar graph type display. Change resistors to select voltage ranges and indicated steps: 5V or 8V in 1/4V steps or 12V in 1/4, 1/2 or 1V steps. All parts included. L: 2-3/4" W: 1-7/16" H: 3/8" WT: .2