This set includes approximately 125 blue o-rings to modify the feel of your Filco or other Cherry MX keyswitched keyboard. The o-rings are fitted to the underside of each keycap, and soften the landing of the keys when pressed all the way down to the bottom of the keystroke.
These are slightly thicker than our red and black o-rings 1.78mm apx, to give increased cushioning, 40 shore (standard hardness) and are made from ethylene propylene which is harder wearing than silicone.