The AV-40 is a non-contact voltage indicator with an audible and visual alarm to indicate the presence of voltage, with an operating range from capacitive test point /secondary voltage to 40kV (line to ground). Activation threshold meets ASTM requirements. Can be used as a stand-alone Voltage Detector without second probe. Non-Contact Audible Visual detector for Underground & Overhead Applications. Calibrated threshold is Minimum Approach Distance for each Overhead Setting. Meter Assembly is over voltage protected. Incidental direct contact will not damage the unit.