Yep. Its a two part set up, and youll need both parts. First you have the 'star' assembly that fits into the ASA, then the pin that goes through the 'star' assembly, and IIRC, theres an o-ring on the inside of that Star assembly to alternately block and allow airflow, depending on the positioning of the pin. Im trying to find a diagram of the blasted thing on the 'net, with no luck. Its one of those things that I could fix in my sleep, if it was in front of me, but couldn't sketch a diagram of. (Mainly because I cant draw for beans, and its 2am).