Morris Products 90629 Ground Pipe Clamp, For Direct Burial, 1/2 - 1" Water Pipe Range, 2 -10 Wire Range, 1/4 - 2/0 Screw Thread Clamp for connecting grounding conductors to buried water pipe, copper tubing, or ground rod Copper alloy for strength and conductivity Fits 2-10 AWG wire and pipe ranging from 1/2 to 1" Maximum voltage of 600 UL listed for safety