Bel-Art Quick Disconnects for &frac14; to  in. Tubing; Polyethylene (Pack of 12) (F19730-0002) Reducing coupler for connecting two pipes with different diameters Push-to-connect fitting connects to pipes or tubing on both ends Made of polyethylene for its light weight, durability, and barrier to gases, vapors, and moisture For use in vacuum applications, water lines, and manometers Metric unit measurements for industry consistency