Installation I found quite simple: Everything measure, the two holders screw on the floor, toilet and tighten up.
The holder like me personally not so, because there are 2 plastic wedges in which many holes that WC is then reacted with a chipboard screw (if you can call it that) laterally screwed to it. That may indeed later look optically good, but if you had the toilet because of constipation reduce a couple of times, the keys will be over. Replacement will be difficult.
Conclusion: Good product, but with little weaknesses.