Tru-Flate 21-133 5/16" Male Hose End Barb Type Hose Fitting Brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability Precision machined one-piece construction for strength and durability Use with hose clamp or ferrules (sold separately) 5/16" hose inside diameter x 1/4" male NPT For use in air line systems