Hioki’s non-contact voltage detection and measurement technology place efficiency and safety as priority considerations to protect customers that need to conduct on-site electrical work as part of renovations and expansions of manufacturing plants and buildings. Model PD3129 is a non-contact phase rotation meter that detects the phase of electrical current flow within insulated wires without using metallic contact voltage clips. The green arrow indicates the normal phase, which can be useful for visual reports that document the proper completion of electrical work. CAT III 600 V.