Also known as ball-seat hose nipples, these fittings consist of a barbed shaft with a rounded end that sits inside a female threaded nut. When mated with a male threaded fitting, the rounded end presses tightly against the inside of the male threads for a better seal than a single-piece fitting. Once assembled, insert the barbed end into rubber hose and secure with a clamp or a crimp-on hose ferrule. The nut swivels until tightened for easy installation. Fittings are brass for good corrosion resistance.

NPSM (National Pipe Straight Mechanical) female threads are compatible with male NPT and NPTF (Dryseal) threads.