The Manifold Pressure for the P-Mags is taken off the Sender Manifold using a modified AN fitting tapped to accepted a nipple; Loctite 270 was used on the nipple thread. A Festo âTâ piece allows M.P. feed to both P-Mags. All fitting are model Jet aircraft fuel hardware and these are required to stop any air leaks in the fuel line to jet engines which would cause an engine failure; they are of excellent quality.