IDEX Flangeless Metric Male Nut is specifically designed to connect tubing to flat bottom ports when paired with the appropriate Flangeless Ferrule. This Nut is made of It is made with versatile Delrin (acetal resin). This material allows the nut to resist cross threading or loosening during use. It is for 1/16OD Tubing. This Nut comes is a black, short black and in a short black 10 pack.