".-Compatible for 1 phase 2 wire, 3 phase 3 wire, 3 phase 4 wire systems -11 to 300V (L-N), 19 to 519V (L-L) measurement -RS485 Communication MODBUS RTU (MFM383A-C-CE) -Accuracy of ± 0.5% for voltage & current, 0.1% for Frequency, 0.01% for -PF, 1% for Power, Class 1 for Active,reactive & Apparent energy -CE RoHS certified"