Neoprene gasket question, wall mount

Hello All,

Wall mount toilet blues again. Today I went to a plumbing store. The only neoprene gasket they had was from Zurn but here is the weird thing: It had a hard plastic ring in the inner radius and that diameter was only about 3 1/2 inches. However, the AS Glenwall drawing states that this toilet's waste horn is already 3 7/8 inches. How can that fit?

The other thing that I find strange: The inner diameter of a carrier flange is just under 4 inches and the waste horn of the AS Glenwall wall-mount toilet is 3 7/8 inches. The slack of its mounting holes versus the carrier bolts is much larger than that. This would mean it could ride on the ABS flange with all its weight plus whoever is sitting on it. Or do I misunderstand something here?

In case you have used it: Is the Crane Rexmont toilet good? It seems a little less expensive than the Glenwall, looks better and is almost three inches shorter. This would reduce the stress on the wall it's hanging on. We aren't much concerned about flush performance or noise, it's the guest bath which won't be used at night.

Regards, Joerg.

I have used the Zurn washer for both the Glenwall and the Rexmont.

Throw away the hard plastic packing circle that is inside the rubber washer.
That's just to keep the boxed package from being squished.