Hagen Ultra Valve - Ganged - 4 Way - All plastic construction - Will not leak up to 5 p.s.i. - Molded design, no seal rings, screws, rivets, joints or seams - Hanger fits all standard aquariums The ELITE 4-way air control valve allows you to run up to 4 air driven products at once. Each valve has a flow adjuster which enable you to regulate air output to each devise. It is leakproof and suitable for fresh or saltwater aquariums Info from Hagen