Installing on end and corner posts when an inside connection is desired. This special electric fence insulator is ideal for use with high-tensile wire at end and corner posts. Firmly securing an electrified wire to corner posts without loss of energy through the fence posts. Fastening electrified wire to corner fence without losing energy. This insulator is for 9 gauge through 12 Gauge ACSR wire and aluminum wire, all wires (both regular and heavy duty).