Extension Arm (Hot Arm), 2.5IN X 72″ Long – 2 Wire Holder The Epoxiglas® Extension Arm is designed for use on voltages up to and including 15 kV where reconductoring or insulator replacement is necessary. The Epoxiglas® Extension Arm can be used on voltages up to 34.5 kV providing the wireholders are fitted with M4805-7 insulators. The Extension Arm is suspended under the crossarm by brackets to enable to conductor to be removed from the original crossarm and placed in the wireholder mounted on the Epoxiglas® Extension Arm.