Part number C3. Fits up to 1 1/2″ O.D. pipe. Stainless steel bolts. Used to bond conductor cable to pipe conduit. Available in bronze or aluminum. Use number C4 for larger pipes up to 2 inches. C4 is for Copper conductor and AC4 is for Aluminum Conductor.
Bolt tension connecters are the best. You tighten it well enough and you never have to worry if it will come loose, especially in concealed systems. It’s well worth the extra money. It’s all we use on our installations.