The Snap-on Digital Display Circuit Tester (EECT400) has an LCD display that provides a “no guess” voltage value of the circuit and a backlit LED that indicates red for power or green for ground. It provides surge-protected +-0.3v accuracy from 3 to 19.99v, plus the computer safe <10mA circuit draw allows for confident testing. With the EECT400, technicians will have one hand free to wiggle wires, replace a fuse or operate a switch. Another important feature is a solid copper clip for maximum electrical signal transfer.