Our Flangeless Ferrules are excellent for connecting most rigid or semi-rigid tubes, including tubing manufactured from fluoropolymers (FEP, PFA, ETFE, ECTFE, etc.), PEEK, PEEKsil™ or stainless steel. Manufactured from Tefzel (ETFE) it offers superior chemical resistance. It has a 5/16-24 Flat-Bottom port configuration and is for 4mm OD Tubing. It comes in natural and a 10 Pack of natural.