Description:If you only have a pump、 but there are several small fish tank needs encouragement、 how do? Select the 3 Way T Connector Tubing Aquariums Air ValvesFeatures:1. Easy to connect hose.2.Three-way plastic valve can be used as an in-line valve to control air flow from pump.3.Fits standard air line tubing aquarium and CO2 tubing with inner diameter about 4 mm.4.Help to increase oxygen and keep air fresh、 create healthy environment for your fish.5. Diameter:4mmPackage included:1x 3 Way T Connector Tubing Aquariums Air Valves