These plates and screws seem to be put up for sale haphazardly. There are 6 screws in each tiny bag but only 4 on the plate. The screws don't go all the way in and stick out. I replaced these screws with something else because one screw broke and lost its head. Remember that the slab is of good thickness. The blue protective film on the disc is of poor quality and difficult to remove completely. Some of the foils were partially removed on arrival and the panels had scratches.