The Extech DVA30 is the only dual function current/voltage tester in one device designed for electrical testing. It detects AC voltages from 12 V to 600 V and AC currents from 200 mA (from 5 mm distance) up to strong currents of up to 1000 A from a distance. Adjusting the sensitivity increases or decreases the sensor's trigger threshold. Audible and visual indicators show current or voltage. The DVA30 can be used to trace concealed cables in walls and floors, detect live cables and trace current flows behind walls, in pipes, through concrete or underground. The sensitivity is high enough to trigger at low voltage HVAC or similar signal levels.