OWON Bi-directional WiFi Home Energy Monitor with 2 Clamp Main Specifications Wi-Fi 802.11 B/G/N20/N40 2.4GHz BLE Bluetooth 4.2 Low Energy RF Characteristics Operating frequency: 2.4GHz Internal antenna Operating Voltage 90~250 Vac50/60 Hz Calibrated Metering Accuracy 100W Within 2W >100W Within 2% Reporting Cycle Every 15 seconds Din Rail 35mm Clamp diameter 80A (default):10.6mm 120A (optional): 16.7mm Clamp cable length 1m Operating environment Temperature:-20~+55 Humidity:90% non-condensing Certification CE Weight 85g (One 80A CT) 150g (Two 80A CT).