1pcs Stainless Steel Aquarium Switches Regulator 1 To 3 way High strength Anti-Rot,anti-high pressured, anti-acid and alkali,prevents from water flow return. Suitable for CO2 supplying system,O2 supplying system and air pump.
Works great at a good price - ordered two of these and they're easy to regulate and they're cheap! Local pet stores will charge up to $10 for the same product, when these do the exact same job just as well. Being used to regulate air pumps and sponge filters for my fish tanks.