Quest o-rings size

[J Yim]

Hey all
I was wondering if any one knew the oring size for the last and biggest oring on the outer bolt sleeve thing. Ive gotten all the sizes except that one. Is it a 019 or a 018?

Thanks!
YimSta007
JYim

[haser]

We use an 018 oring at the back if the bolt.

Rich
FEP Production Monkey