Need Help- O-ring on bearing carrier

[BULLET99Z28]

Putting a bike together from parts, and looking at the online parts Fiche it appears that there is an oring that is in between the rear caliper stay plate and the carrier. I assume thats what the grove on the inside of the caliper stay plate is for. Am I correct?

[eastside 400]

yes, it really isnt needed.

[DnB_racing]

Originally posted by eastside 400
yes, it really isnt needed. but it deos keep it from being loose and rattling a little, but no big deal if its not there

[dyno]

Actually 2- 1 in the plate and 1 between the plate and carrier!