39" (1m) Non-Contact current detector (up to 1000A) The Extech DA50 Telescoping AC Current Detector, 1000A detects AC Current in shielded wires, wires behind walls, metal circuit breaker and junction boxes. The telescoping probe extends the reach of the DA50 by 36 in., for a total reach of 39 in. This model features sensitivity adjustment to increase or reduce sensor trigger threshold.