Thin brown paper covering, usually given away when purchasing single beers or malt liquor at convenience stores. Not shown to actually keep the product cold, but does serve to absorb condensation from the exterior of the can or bottle. Also know as a small brown paper bag.
Store clerk: Would you like me to put that Steel Reserve 211 in a bag?
Crackhead: No, thanks, sir. I will however take one of the free ghetto koozies that you normally give me.