3.2.1 Plastic Isolation Bumpers
Plastic isolation bumpers are used on the bottom side of the board to isolate it from the surface on which it is mounted. The height of the isolation bumpers on the bottom side is 2.8mm and the recommended part is SJ-5076 from 3M. Other adhesive feet might work as well but it is very important to have the same height because otherwise extensions will not align well when connected.