Abstract: A device for mixing and dispensing two or more reactive liquids into a homogeneous stream. The device includes a mixing chamber with two or more inlets for introducing separate liquid components into and an outlet for dispensing the mixed liquid components from the chamber. Separate passages connect each inlet to a separate source of liquid. Also, each passage includes an on-off valve disposed between the liquid source and the inlet and each passage also includes a pressure opening truncated cone pin check valve seated in close position in a truncated inlet to the mixing chamber.