Anyone know what the heck these things are? I’ve never seen anything like it. They are not supporting the copper piping and the hot water isn’t that hot! Thanks in advance.
Heat fin, but not much of it to amount to anything.
I recall some years back they sold some that were about 6" wide and looked like an accordion to wrap around your pipes in hot water heating systems. Same principle as the fins on the pipes of baseboard heaters.
The ones you show look like head gashers!
Copper tubing dielectric corrosion enhancers. 
Well, with that fancy name, I hope that works better than the attempt for heating purposes. 
Darren, thats awesome. Thanks for the good laugh.
Rat barriers. Keeps the rats from running across the pipes.
Valid point. Unless there’s a grommet, it’s sheet metal in contact with copper, but the sheet metal is least noble and will corrode first.