For use with plastic, stainless steel, copper and other tubings. Leak-proof and corrosion-proof. Simple to install: just cut tubing end square, insert into fitting without disassembling and tighten ferrule nut for seal. No flaring required. Molded of White Polypropylene, Kynar (PVDF), Nylon and Acetal. Operating Pressure: Standard Ferrule Nut - 50 psi, Plastic and Steel Gripper Nut - 220 psi Note : When soft tubings such as Vinyl or Polyurethane are used, Tubing Inserts should be added.