OPEN BOX - Non-Contact AC Voltage Detector and Phase Sequence Indicator (ET400-OB)The Triplett ET400 combines a Non Contact Voltage and Phase Sequence Tester. It has dual AC voltage ranges: Read More > DESCRIPTION The Triplett ET400 combines a Non Contact Voltage and Phase Sequence Tester. It has dual AC voltage ranges: 12 to 1000V and 100 to 1000V with high sensitivity that allows it to detect low voltage AC wiring commonly found in doorbell circuits, thermostats, control circuits, and video surveillance camera power. In addition,