Thanks for that info, Zee. Considering that 'button' in the center appears to be the only place for oil to flow through the center tube, I was hoping it was something like that.
I'll admit, the first one of these I opened up, I thought that someone had somehow pushed some sort of plastic tube down into the center hole and ruined the filter. It's unlike any other filter I've ever seen.
Looking back at the pictures posted by Car51 of his LF641, it appears these filters are quite robust, and it seems that this one, at least, laughed at the 7,500 oci. Does anyone here have any experience with the LF483, and are they similarly robust? I ask because I bought 3x LF483 and 5x of the Federated version (LF483F), and I'm curious if I can run those for 7,500 as well.