"Bottoming out" is a term used to describe when a key stroke is pressed all the way down where the stem of the switch hits the inside of the switch case. This causes a "clack" from the collision on mechanical keyboards. Switch sound dampeners are soft rubber O-rings that can be installed onto every single keycap stem to cushion the landing of the switch by stopping the key stroke just short of the point of bottoming out. This also very slightly reduces the max travel distance of the switch (0.2-0.4mm of 4mm total travel distance; varies by O-ring type).
This modification is popular among mechanical keyboard owners from around the world. Since most people will bottom out at least a fraction of their keystrokes, the switch sound dampeners will cut away extra noise giving your mechanical keyboard a consistent sound output while typing. The added shock absorption can also help with finger fatigue during long typing sessions.
To install the O-rings, simply slide your keycaps off, pop the O-rings into position, and slide the caps back on. Manufactured from silicone rubber, this 50A O-rings won’t slip from position or crack with use, giving you a mechanical keyboard modification to last a lifetime.
Note : Some keycaps, such as the ones found on Cherry Corp keyboards have different stem lengths and will not work properly with this O-rings.