Apr 24, 2019 - 07:59 AM
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The SlimEdge "should" lay flush on your toilet porcelian, unless of course your toilet has a slope. Check to make sure the existing mounting bolts from your toilet lay flat, you may need to substitute these bolts.
Another alternative is to add foot pads in addition to your seat ring to make up the height difference.
We would not be able to recommend any other brands that would be more comprobable.
Source: Toilet Types and Sizes