These fittings have two sleeves for extra gripping power. They bite into steel tubing as you tighten the nut to form a strong seal.

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 hose and secure with a clamp or a crimp-on hose ferrule.

Low-profile barbs and a longer first barb allow for a smoother, easier installation than other barbed fittings. Slide the barbed end into hose and secure with a clamp.