Super Flangeless PEEK Nuts delivers the highest pressure holding for flat bottom fittings that we offer. Manufactured from biocompatible PEEK it delivers excellent chemical resistance. Our short not has a 1/4-28 Flat-Bottom port configuration and is for 1/16″ or 1/32″ tubing OD. It comes in natural, blue, black, green, gray, orange and red. Brochure