The Hagen Ultra Air Valve allows you to run up to 5 air driven products at one time. A flow adjuster on each valve enables you to control air output to each devise. The valves are leak proof and can be used with either fresh or saltwater aquariums. There are no seal rings, screws, rivets, joints or seams. Hangers fit all standard aquariums. The ultra air valve will not break up to 5 p.s.i.