Multi-Level Dual UFO Perc BongThis little powerhouse has been designed to give the best possible cooling and filtration for a bong of this size. After your smoke has travelled down the removable diffused downstem it travels up through a pair of UFO percs that create a cloud of tiny bubbles and cause the temperature of the smoke to plummet while at the same time pulling out any dirt or particles that you don't want to inhale to a give you a smooth, tasty hit. Once through the