Abstract: A series of flow control mixing devices used in a mixing chamber in a spray gun, or the like, to more thoroughly mix multi-components in a mixing chamber, consists of three different types of cylindrical mixing elements sealingly held in the chamber. Each of the mixing elements contains a pair of inlets, a central chamber and an outlet, connected together so as to mix entering components therein, and passing these mixed components to the outlet. Two of the types of mixing elements include a mixing reservoir or chamber formed on a top surface thereof. A plurality of second mixing elements are secured over a first or downstream mixing element, and a final or third mixing element is provided upstream of the other elements. The first element includes a spacing member on the lower surface, and all the mixing elements include O-ring seals held in grooves formed on the outer periphery thereof.