This was at a sale I went to I never saw one before.
And here is hoping you never have to use it!
That's nifty how it has the hooks to fit into the clincher rim. I didn't know they made them like that.
I think that is known as a "tire boot" used to cover a badly worn spot, cut, or split on a tire. My grandpa used to make his own by cutting up another tire and wrapping baling wire around it. In fact, when he bought a new set of tires, he made boots out of the old tires to completely cover the new ones. He said that was the only way he could drive on the Ozark backwoods trails without having a flat every few miles.
Some were just laced on like a shoe as you noted. The fancy ones hooked to the clincher rim!