The Super Mite 71 will automatically select the higher or lower of two pneumatic inputs and pass it downstream while blocking the other. Capable of almost instantaneous selection, the Super Mite 71 can separate pressure differentials as low as a tenth of a psi. Although ordered as either high or low pass, the Super Mite 71 can easily be converted in the field from one to the other. The Super Mite 71 can be relied on to open or close valves when a signal pressure drops or rises past a determined value. They can also be used to prevent a valve from opening or closing beyond a critical point.