The stock R40 comes with two acrylic pedestal feets, but if you move your case around a lot, or have it standing on a rug, this kit would probably come in handy! This hard feet kit will lift the case up 20 mm from the ground, where the original feets lifts the case up 12 mm.
1 x R40 base plate with threads
4 x Rubber feet
4 x M5 Bolts