A bubbler is any pipe smaller than a water pipe that uses water to filter smoke and vapor. Most bubblers have no removable components, though some larger upright bubblers come with component bowls. There are two major styles of bubbler: hammer bubblers and upright bubblers. Hammer bubblers feature a bubbler chamber connected at a 90° angle to a straight mouthpiece. Two glass feet on the base of the bubbler chamber form a tripod with the mouthpiece to stabilize the bubbler between uses. Upright bubblers feature a bubbler chamber with a single, broad glass foot and a mouthpiece that extends from the side of the chamber at a 45° angle.