A portable battery-operated voltage source that can verify the correct functioning of 2-pole voltage detectors. With automatic operation when probes are inserted into output terminals and 5 x stepped nominal output voltages. 10W output power drives high loads. Features a magnetic base, low battery indicator and extended battery life. 50, 100, 230, 400 & 690V Output Voltage LED Indicator Automatic Operation 10W Output Power Magnetic Base Low Battery Indicator Extended Battery Life 50, 100, 230, 400 & 690V Output Voltage LED Indicator Automatic Operation 10W Output Power Magnetic Base Low Battery Indicator Extended Battery Life