It rests between two metal doors amounts at home, so I will use that disc caoutchoux to avoid damaging the walls but if do not have the opportunity to let it rest on your doorposts then you need to use the fixing screws supplied with the bar.
There is even a small metal rod slip into a hole in the middle of the bar to tighten it very hard if necessary.
40 For you will have a bar that you can store 50 years!