Internal zero dead volume reducing ferrules are used with standard Valco internal fittings, which have a male nut and a female fitting detail. The ferrule’s integral pilot fills the pilot cavity between the end of the ferrule and the bottom of the detail, yielding a zero dead volume fitting. (Not for use in Cheminert HPLC PAEK valves (C1-C5 series) since the fitting detail in these valves has an extended pilot length.)