These Captain O-Ring keyboard switch dampener o-rings can be quickly installed on the stems of your keyboard keys to prevent keys from bottoming out. Bottoming out occurs when a key is pressed down to its limit, causing the key stem to collide with the switch casing.
Thin 0.2mm o-rings for keyboard. Made my clacky switches much more plocky / silent when bottoming out. Will probably buy another pack to redo another keyboard.