Parker Hannifin 393P-4-4 Poly-Tite Chrome Plated Brass Through Type Insert Fitting, 1/4" Compression Tube x 1/4" Plug-In Stem Designed for Use with thermoplastic tubing Machined in tube support Black acetal copolymer sleeve Brass sleeve available for soft metal tubing Knurled Nut for ease of hand tightening