IDEX Flangeless FlushNut Fittings are designed to include both a nut and ferrule for yIDEX convenience. Flangeless fittings are excellent replacements for flanged fittings. Flangeless fitting are dependable, easy to use and easy to replace. FlushNuts offers the answer for those tight-space applications where nut heads often interfere with each other. It has a 1/4-28 Flat-Bottom port configuration and is for 1/16 OD Tubing. IDEX Fitting System comes with P-200 ferrule.