These are parts I've used to do two things...
Enable me to fit little 6mm spacers to the feet to lift the machine up a bit. Mine was rocking on the centre section. I'm not sure if it's just my machine but adding these solved it. I used M4x16mm screws. The chamfer goes to the top.
- Added these little plastic washers to stop the side plastic bits rattling. You might / might not need these.
The A5 is a great printer, very happy with mine :-)