Looking for a particular type of air valve Answered

So 2 parts to this question, one is what would it be called, the other, where would I find it.
I am looking for a valve  that would have 3 stems, for lack of a better term.  One one end would be the source, another the output and the last would alternate between pulling from the source and pushing to the output.   Any Googling tips?  Not looking for anything industrial, simple small plastic valve would suffice.