Although the bottom was concrete, it could not be used without stopping. The place to hit the concrete was not rubber but it was in a state that it slipped because it was made of resin. I am sorry to have purchased it so much.
Adhesive tape was stuck on not only the magnet but also the main body. I did not use an auxiliary plate for wooden doors, but there were ribs that seemed to stop slippage. I raise and lower with my feet everyday, but I am fulfilling the function without any gaps.