looks like just a basic "valve" to me. You might have trouble finding one that small at HD
but it's worth a shot. You just gotta find something small enough to fit the, assuming, airline size tubing that has a flow restrictor that you can adjust. Go to HD
and find an assistant, I've found they're quite helpful, even the plumbing guy when I was asking questions about making stuff for a fish tank, he was confused at first, but then when he realized what I was trying to do led
me to exactly what I was looking for.