Wago passive isolator 1 channel wago 857 451 the wago passive isolator 1 channel is a high quality transducer for din 35 rail the 1 channel passive isolator filters and electrically isolates 0 4 20ma analog standard signals no additional supply voltage required safe 3 way isolation with 2 5kv test voltage to en 61140 wago 857 451 passive isolator 1 channel