pretty common, i know a guy who makes them out of of lighters (the colored see through crack torches) and sells them to local smoke shops for like 7 bucks a piece. they definatly work, not the best, but if u wanna be cheap and have a lil pipe for a quick bowl pack, sure why not
Dude I just broke mine it cost me $8 bucks at the shop there cool if you don't mind not having a Carb but they actually do cool down the smoke way smother then a spoon