This combo kit includes 4mm plate foam, 2mm case foam with hotswap cutouts and 2 round 10mm plugs to fill the holes where the feet screw in.
Installation requires taking the board apart, putting the plate foam inside, slipping the PCB back into place GENTLY, putting the case foam on the PCB, putting the 'acrylic' (plastic) diffuser back into place, press all of the plastic plugs in tightly to hold everything together and then screw the top half to the bottom half.
These foams are designed to fit the CTRL - a keyboard designed and produced by DROP (previously Massdrop).
Please take note that there are currently two, scratch that, three versions of the High Profile variant of the CTRL in circulation. The new version works for all three variations of the switch plate but might still need small alterations and adjustments to fit the diffuser. We're working on getting the case foam design updated to fit the newer diffusers.