These 1/2" PVC air manifolds are made with your choice of valves. The air supply inlet is a 1/2" FNPT with 1/4" barb (62014) which fits 1/4" I.D. tubing. Type P is made with plastic (VPL12-B), B with brass (VBR12), which fit 3/16" I.D. tubing (see Index to locate valve descriptions). Each manifold includes two 1/2" Clic fittings for mounting to a flat surface.