Ring Main Unit Wireless Phase Detector apply for ring main unit phase detecting of power distribution system,and phase, frequency, phase sequence test. 1. Model No.: ETCR1520 2. Phase detecting voltage : AC 1V~600V 3. Phase detecting distance : 30m 4. Phase detecting distance: 0°~360° 5. Frequency Range : 45.0Hz~65.0Hz 6. Power Supply: Host: 3.7V, 2600mAh Rechargeable lithium battery; Detector: 3.7V, 600mAh Rechargeable lithium battery