Pocket pen style voltage alert detector tester alarm features detects AC voltage90V~1000V without metallic contact. Entire outer surface are non-conductive for safety helps avoid high voltage shock. - Detects AC voltage without metallic contact - Red LED voltage indicator convenient for operate in darkness - Fits in a shirt pocket for convenience - Entire outer surface are non-conductive for safety helps avoid high voltage shock - Quickly locates the hot neutral and ground terminals in any receptacle - Voltage Sensitivity: 90~1000V AC - Powered by 2 * 1.5V AAA batteries (not included)