URO coolant transfer pipe - can't seat o-ring

[VW-Fritzi]

I’m talking about the largest O-ring that comes with the kit, pictured at upper left here:



I want to make sure I’m trying to install it correctly, as I think the O-ring that came with the transfer pipe kit shipped inside out.

When I hold this O-ring in my hand before stalling it, should the outside face of the O-ring be completely flat, and the inside face have a bevel to it? This it how it was shipped to me.

Or should it be the other way around, with the bevel on the outside and completely flat on the inside?

Put another way, should the beveled side be in contact with the transfer pipe, or should the flat side be in contact with the transfer pipe?

Like I said, the O-ring shipped to me with flat side “out”, but when I tried installing it that way, it didn’t seem to fit AT ALL. So I tried turning it inside out so that the bevel was on the outside, and it seemed to fit into the groove much better, but I still can’t get it all the way flush.