HW90 Beeman RX1 Inertia Piston

[Scrinja]

Hi guys anyone got the oring size for the Inertia floating piston
I did have it all wrote down in my note book but thats gone missing
It will/should be in Metric as Germany dont do Imperial which is generaly banded about all over the net
Thanks in advance Guys
And yesi know they are cheap enough and yes i have ordered a couple to measure when they arrive
And yes im a Dummy for losing my book

[Scrinja]

So it seems the Answer is a secret then ??
Where are all the 90 Rammer Experts hiding on here come to the rescue please lol
No one knows on the yank side either GTA or the Airgun Nation etc etc
Why the big secret ??