Anyone know the size of the o-ring for the FPR (new age)?

I don't have any subaru dealers nearby, so need to order by post from somewhere, but not sure what size it is. I tried the halfords ones (metric set), but it leaks like a good'un.

 

Just in case someone stumbles upon this thread by a search etc, the part number from Subaru for this o-ring is 16699aa000. Cost 7.50 each (ouch)

When I receive it, I will measure it up and post up the o-ring measurements so that a generic one can be found, because 7.50 is just a *massive* rip off for one small o-ring.

 

I know I'm the only one talking on this thread, and it's 5 years later, but the top o-ring from an injector works OK instead of the official o-ring (or at least it's working OK for me).