Test Voltage Range: 90-1000V AC Frequency Range: 50 to 500 HZ Safety ... II, 1000V Blue Non-Contact Voltage Detector Pen AC Volt Sensor Tester Alert 90~1000V LED, YFT397A ... useTotally insulated, no exposed metal or conductive partsIdeal for testing AC cables, circuit breakers, wall sockets, junction boxes, fuses ... . Blue Non-Contact Voltage Detector Pen AC Volt Sensor Tester Alert 90~1000V LED, YFT397A