Mounted to DIN 3 rail using DIN mounting clip located on rear of unit, Model HGLND-D2-12 protects differential data or balanced digital or analog lines from transients and surges. Three-stage lightning protector comprises differential gas discharge tube, pair of current limiting series resistors, and low capacitance diode array. By utilizing 3-stage system, Model HGLND-D2-12 is capable of handling surges that single-stage protectors cannot.