I have a somewhat mysterious service ground apparently underneath a concrete entryway. All that is visible now is a heavy gauge bare copper wire coming through the cement. When the cable company hooked up my internet they bonded the coax ground to this service ground using some sort of clamp:
What is this square clamp called? I have pored through hundreds of Google Images for "ground clamp" and "square ground clamp" and "copper ground lug" and whatever else I can think of and am not finding something like this, which is apparently designed for bonding in this sort of situation.
I am adding some of my own antennas and need to bond their grounds to this same service ground wire. So I need something like this that can split into two pieces around the middle of my service ground wire, and clamp it tightly onto the end of an additional ground wire.
(Rather than directly connecting my lightning arrestors, in actuality I'll probably be driving a second "known quantity" ground rod nearby, and bonding that to the service ground — but then I'll still need basically the same sort of clamp.)