Threaded Signal Surge Protector 1 pair, Maximum continuous operating voltages (Uc) 65VDC & 50VAC, Maximum discharge current (Imax) at 8/20µs 5 kA per line (10 kA common mode), Voltage protection levels at @ 1 kV/µs between <100V (L-L) & < 350 V (L-PE ). Shunt connection, IP67 (installed) thread size M20 x 1.5. Ideal for twisted pair signalling schemes, installed directly at field equipment