The GM-3-Q Bronze Grounding Clamp is used to ground copper code conductor to flat surfaces. Cast from high strength, electrolytic brinz to provide reliable grouding connections, high strength silicon bronze hardware for long term reliable assembly. Accomidates a wide range of conductor sizes, incorporates spacer plate to separate conductor from mounting surface. Meets cULus 467 for grouding and bonding, suitable for direct burial in earth or concrete. Hex Size 1/2".