UL Listed for direct burial in earth or concrete. Screws are silicon bronze. This incredible ground clamp can handle just about any size ground wire and just about any application. UL Listed for direct burial in earth and concrete, it can be used with rebar, water pipe, copper tubing and ground rods up to 1 inch in diameter. Assembled with tough, stainless steel screws. Will accommodate ground wires from 8 awg to 4/0 awg. Used to connect bare copper wire to water pipe, ground rods and rebar for bonding. Assembled with copper screws and UL Listed for direct burial in earth and concrete. Can accommodate ground wires up to 2 awg.