Argus 7SR158 voltage / frequency relay, case I/O and fascia: 3 VT, 6 binary inputs / 8 binary outputs, 10 LEDs, measuring input: 40-160 V, 50/60 Hz, auxiliary voltage: 24-250 V DC / 100-230 V AC, binary input threshold 88 V DC, standard version: USB front port, RS485 rear port plus additional rear electrical Ethernet RJ45 (x2), IEC 60870-5-103, Modbus RTU, DNP3 and IEC 61850, push buttons – down and right arrows, protection functions: Standard plus 78 and 81R