So I recently received some black o-rings from Aliexpress which costed me only $5. They measure 8mm(outside diameter) x 5mm(inside diameter) x 1.5mm(thickness). Having ordered them cheaply from an Aliexpress vendor and having never used o-rings before, my expectations were low. After installing them on Cherry MX Browns on a POK3R, here are my thoughts:
- They noticeably reduce travel distance
- They're slightly squishy upon bottoming out compared to hitting the plate, however firm enough to still feel satisfying in my opinion. I could see some people not liking this feeling though as there is a distinctly satisfying feeling/sound of bottoming out on Cherry MX switches
- They slightly reduce the noise created by the MX Browns by softening the bottoming out sound, but they by no means "silence" them
- They reduce fatigue due to a softer bottoming out and a smaller distance to press the key before bottoming out, provided you adjust and type lighter
In conclusion...
I bought o-rings partially to try them out and partially for ergonomics. Note that I use proper typing form. For my purposes, I feel like I am putting less strain on my fingers while typing and although I was most worried about losing the "clack" sound, I enjoy this softer sound as well. If you are interested in improving ergonomics and don't mind sacrificing the "clack" sound and snappy bottoming-out feeling, then for $5 they're definitely worth it! However, if you have no issues with ergonomics and/or love the sound and feeling of bottoming out on Cherry MX switches, then o-rings may not be for you. At the end of the day, if you can find some for cheap like I did, give them a try and see for yourself!
Here's where I found mine, however there are many other sources for higher-quality ones:
http://www.aliexpress.com/item/Free-delivery-with-tracking-number-Black-Color-Bag-of-105pcs-Keycap-O-Ring-Switch-Dampeners-For/1305826637.html