Dual rated ground clamp for copper and aluminum cable. GC-A ground clamps are UL Listed for use with either copper or aluminum conductors to copper water pipe, galvanized pipe or steel conduit. All clamps are constructed from tin plated high-strength extruded aluminum alloy. Penetrox oxide inhibiting joint compounds are recommended for all aluminum applications. Clamps are dual rated for both copper and aluminum conductors. Maximum flexibility of application. All connectors are tin plated. Provide low contact resistance and prevents galvanic corrosion. All clamps are range taking.