Brass plug part of the vacuum economizer used in multiple models of Stromberg carburetors: DXR-2, DDR-3, URO-2, UR-2, UR-23 and UUR-2. For use in many automobiles produced from 1928 – 1935.
Part of Stromberg P-15479, vacuum economizer pump.
Thread length: .162
Length under head: .250
OD head: .4375