Hardware
Captain O-Ring switch dampeners, blue 40A-R
On my Cherry MX Blue boards since February 2023
Twelve dollars and half an hour takes the clack out of a clicky keyboard you already own. The cheapest upgrade on this page.
Most of my typing is on Cherry MX Brown switches. Browns give a soft bump you can feel without the noise, and for the work I do they are the right answer nearly every time.
I also own boards with Cherry MX Blues. Blues are clicky — that is the whole point of them, and I like the feel — but the noise is real, and most of it is not the click at all. It is the key bottoming out and the stem hitting the switch housing. That part you can fix for twelve dollars.
Quieter is only half of it. The other half is what your fingers feel. Without a ring, every keystroke ends in a sudden hard stop against the switch housing, and you take that impact a few thousand times a day. The ring turns that stop into a soft landing. After a long day of writing it is the part I notice most.
An O-ring is a small rubber washer that sits on the key stem and catches the key before it lands. Pull the keycap, drop the ring over the stem, put the cap back. The packaging says four to five minutes for a whole keyboard. Set aside thirty. A full-size board has over a hundred keys, and you handle each one twice — once to pull the cap, once to put it back.
These are the ones I buy. They are EPDM rubber rather than the cheap black buna rings, which go hard and crack in this job. The 0.4mm version shortens key travel slightly as well as quieting the landing. A pack of 135 covers a full-size board with spares.
One note on where to buy. I have always ordered these from Amazon, and on the day I checked they were a dollar cheaper direct from the manufacturer. A dollar is not a reason to change your habits. It is a reason to look before you click, which is the only thing this page is really asking you to do.
What is good
- Removes the hard stop at the bottom of every keystroke, which is easier on the fingers over a long day
- Quiets the loudest part of a mechanical keyboard for about twelve dollars
- No tools needed, and nothing about the keyboard is modified
- EPDM rubber instead of buna, so it does not go hard and crack
- Completely reversible — pull them back off if you do not like it
- 135 rings covers a full-size board with spares left over
What is not
- Budget half an hour to fit a full-size board, not the four to five minutes on the packaging
- Shortens key travel by 0.4mm, which some typists dislike
- Quiets the bottom-out, not the click itself — a Blue is still a Blue
Where to buy
Every seller I found, including the ones that pay me nothing. Prices are what they were on the date shown — check before you buy.
| Retailer | Price | Checked |
|---|---|---|
| Captain O-Ring (direct) | $11.99 | 2026-08-15 |
| Amazon | $12.99 | 2026-08-15 |
No used listings appear here. Factory refurbished is included where it carries a warranty, and is labeled.
Other reviews
- Logitech Pebble mouse A quiet, slim Bluetooth mouse for people who live on the keyboard and reach for the mouse now and then. The silent click is the reason to buy it.
- Monitors — LG, and the Samsung I miss The LG UltraFine 31.5-inch is my daily driver and easy to look at for hours on end. Buy the highest resolution you can afford — it is the specification you feel every day.
- Das Keyboard My number one keyboard, and the one I keep coming back to after trying others. Buy once, cry once.