Gallagher's fault finder is a top of the line current meter and digital volt meter built to help you identify and locate faults in your electric fence line. The fault finder measures voltage, current and shows the direction of current flow. The extendable voltage probe allows you to easily measure voltage at points of difficult access such as cut out switches and energizer terminals. While sized to fit conveniently in your pocket (2-1/2 in x 5 in), the fault finder is still easy to read and lasts up to three years on batteries that come included with the unit.