You get all 3 brass regulators for one price. They are off of 3X and 4X rivet guns. They have standard 1/4" NPT threads. Surplus from Boeing.
Anest Iwata Air Pressure Gauges for Gun Air Regulators Pressure Air Regulators
Wilmar Air Regulators / Valves M693
3 Way Air Hose Manifold Quick Coupler Connector Brass Fitting Adapter Splitter
Husky 5-Piece 3/8" Air Hose Repair Kit Brass Barbs Steel Clamps 831 157
AES Industries 7347 3/8 x 1/4 in. Brass Air Hose Repair Kit
