Power Brake Hose Check Valve ('65 Formula S)?
The check valve is the round (about the size of a half dollar) fitting held into your booster by a rubber grommet- in your case it has 2 hose barbs that you attach your vacuum hoses to.
Similar to this:
Edit: Oops, my mistake. This is for the later booster.
The check valve is the round (about the size of a half dollar) fitting held into your booster by a rubber grommet- in your case it has 2 hose barbs that you attach your vacuum hoses to.
Similar to this:
Edit: Oops, my mistake. This is for the later booster.