These Upchurch Scientific / IDEX Health & Science / Biotech Fluidics Flangeless PEEK Fittings are designed to include both a nut and ferrule for your convenience. Flangeless fittings are excellent replacements for flanged fittings. Flangeless fitting are dependable, easy to use and easy to replace. It has a 5/16-24 Flat-Bottom port configuration and is for 1/8″ OD tubing. This fitting comes with the P-300 ferrule.