Exhaust Hangers

I believe they are exhaust hangers. Anyone know what these are and/or how they work?

 

The bolt thing at the bottom probably attaches to something on the frame (or the muffler). The rubber ones I remember had a steel bracket riveted (or bolted) to the top hole that would fit under a muffler clamp on the pipe (or would have a bolt p*** through to a hole in the frame). Usually one end or the other had a removable bolt that could be inserted into one of the other open holes to adjust how high or low the exhaust hung from the ch***is.
There were probably 20 different options of the same 4 hole rubber strap with differing metal straps attached to one end, that were used for different car makes or body styles over the years.