Morris Products 91664 Ground Pipe Clamp, With Adaptor Serrations, 2-10 Wire Range, 2-1/4" - 4" Water Pipe Range Copper Ground Pipe Clamps - Serrated Collar - These Copper Ground Pipe Clamps have a serrated collar to accomodate adaptors to ground armored cable or conduit to water pipes Cast Copper Ground Pipe Clamps have serrations that would match the serrations of the armored cable or conduit adapters Used to Connect Copper Grounding Conductor to Water Pipe, Ground Rods & Copper Heater Tubing etc. Manufactured from High Conductivity Cast Copper alloy Supplied with Steel Screws, Zinc Plated for corrosion resistance