LN Eng IMS Bearing Question

[Muskoka Minute]

Evening Guys

I'm considering purchasing the LN Engineering IMS retro fit single row bearing.

My question is I don't see how it keeps the oil in?

On the factory IMS it has an "O" ring on the center stem which the flange goes over
to keep the oil in.
This makes sense to me.

But I don't see how the LN bearing achieves this.

I look at pictures on line and it does not show how it does this.

Does it have a groove cut on the inside on the flange (for an "O" ring) where it slides
over the center stem? (in reverse of the OEM system)

I just like to know how things work before I drop a bunch of cash.

Thanks
Bart