1911 fill valve oring
 

I just blew off two of my fill valve orings (on two different mags)...

They filled in, then when I took off the AI adapter, the oring that's around the nozzle just... jumped out while all gas came out.

It did the same thing on both mags.

I'll need new orings, so do you know what size I need? I'll try to find one at my local Home Depot.

Is there anything else I should do to prevent leaks from the fill in valve and to ensure it doesn't happen again?