Water Pump seal OEM? Where does the white seal go 2005 trx450r

[OutlawEX]

I am rebuilding a water pump for the first time on the sidecover. Well the OEM package of course had the aluminum seal and then a white/black seal? When I removed the bearing and seal on the back side I did not see or remove a white seal like what came in the OEM package. Where does this white seal go?