John Guest Acetal Copolymer Tube Fitting, Adaptor, 3/8" Tube OD x 1/4" Flared Female (Pack of 10) Adapter for connecting pipes or fittings of different types Push-to-connect fitting connects to pipes or tubing on one end and a flared female NPT connector on the other Made of acetal copolymer plastic for low moisture absorption and high tensile and flexural strength Working pressure of up to 150 psi Meets NSF/ANSI standards 14, 51, and 61 for quality assurance