I bought this raised seat as my wife had recently had a total knee replacement and had difficulty standing after using the toilet. The four (4) inch rise was idle and relieved the pressure on her knees when standing. The supplied hardware to clap the unit to the unit was adequate but not great; therefore I added two - four (4) inch sections of double back foam tape on the toilet risers bottom on each side. This made this unit to become as one with the toilet - extremely solid. I did remove the old toilet seat cover as the riser did come with a lid. My wife's mobility after PT has improved tremendously and has decided to leave the riser in place - the toilet is the one she uses as it is off the master bedroom. Happy with the purchase.