MARK analog voltmeter phasing set 0-25kv. Dual stick MARK series measure voltage and perform phasing operations from 0V to 75kV. Single stick EM series measure voltage from 0V to 25kV. No batteries or calibration required. Determines in-phase or out-of-phase. Determines underground cable faults. Discharges underground cables and other equipment that hold capacitive charges. Versatile for overhead and underground applications