This Slam Speacilties 4 valve manifold features 2-3/8" inlets from tank, 2-3/8" exhaust ports, 2-1/8" ports to run to pressure gauge and 2 3/8" supply ports one would go to each corner to prevent transfer of air through curves in the road.  Kit includes 4 valve manifold, airline to run to gauge.  Tel Tek Red gauge or viar dual needle gauge. Switches and chrome extensions for the dash. Gauge fits a standard 2 1/16" hole.