This set includes approximately 125 black 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 1.5mm apx thick, 50 shore slightly harder than our red and blue o-rings, and are made from silicone.