Bridgeport Fittings Copper Lay-in Lugs are for use with all grounding applications. the mounting hole accomodates 1/4 inch bolt (not included). The CLI-20 is UL and CSA Listed for Direct Burial. The CLI-20 offers excellent corrosion resistance with stainless steel set screws and high strength copper alloy construction. Wire Range CU only #4-14 AWG.