LASCO 19-6135 Reducing Tee Push-In Fitting with 3/8 x 3/8 x 1/4-Inch OD Tubing, Plastic Plastic push in fitting 3/8 x 3/8 x 1/4-inch OD Tubing, Reducing Tube x tube x tube tee Good for use on PEX, poly, copper OD tubing Clean tubing, push in by hand