Ask politely, and ask for a couple of them. Thats the correct number.
Have you checked you actually have the check valve in your gun? I use a piece of wire, to pick it out, and bend the end of the wire so it cant come off (for cleaning the gun). And pop it back in using the wire aswell. Easy lost though!
liam92 the check valve (aka. flow restrictor) is a small, plastic air port that slows down pressure flow in one direction. Its used to help control the movement of the bolt during firing, or in other words, they reckon its softer on paint all i know is, its certainly better with one!