Pocket pen style voltage alert detector tester alarm features detects AC voltage without metallic contact. Entire outer surface are non-conductive for safety helps avoid high voltage shock. White LED illumination light convenient for operating in darkness. - Detects AC voltage without metallic contact - White LED illumination light convenient for operate in darkness - Fits in a shirt pocket for convenience - Features a alarm prompt sound - 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)