The UFO is a one of a kind design made by the geniuses at Magic-Flight. Simply land the UFO on top of any pub glass for instant water filtration. The UFO is made out of bamboo which is lightweight and very strong. Below the ufo there is a foam seal that keeps the connection to the pub glass air tight. The UFO fits any standard pub glass with a rim between 1.5″ and 3.5″. Two stems are included for tales and shorter glasses.