Suit for 110V, 120V, 220V, 230V, 240V AC low voltage system Measure U, I, P, Q, S, PF, kWh, kvarh, LCD display U, I, P, kWh 6 +1 digits LCD display (999999.9 kWh) LED indicates pulse output Password protection One key for up/down page, one key for programming Small size: 100*36*65mm RS485 port , MODBUS-RTU or DTL645 protocol (Optional) 35mm DIN rail installing, standard DIN ED5002 Standard: IEC62053-21