Fittings have sharper barbs than standard barbed hose fittings to grip rubber push-on hose with no clamps or ferrules required. The more you pull on the fittings, the tighter the hose will grip.Brass fittings are softer than other metal fittings, so they’re easier to thread together. They have good corrosion resistance. Fittings that swivel until tightened rotate 360° for easy installation; those with NSPM threads are also known as ball-seat fittings.Fittings with a threaded end are also known as hose nipples.The optional installation tool (sold separately) allows you to connect large quantities of barbed fittings to push-on hose. Use the built-in cutter to squarely cut the hose without fraying. Then, clamp the hose into the tool’s vise and apply light pressure on the handle to drive into the fitting. NPSM (National Pipe Straight Mechanical) female threads are compatible with male NPT and NPTF threads.Note: To ensure proper connection, the barbed end has to be pushed in all the way, with the hose end concealed by the ring.