It is a piece of a plastic coke bottle. It protects the barrel all the way around and it seemed to pad the barrel more than the aluminum can.
I chucked the barrel in very tightly with no mark whatever on the surface of the barrel.
Loud and clear. In point of fact, this one probably will never be for sale. (Unless it is sold by my widow.)
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson