This article from KeyChatter.com will help you identifying your keycaps - but if you are still not sure, it will be my pleasure to answer you as quickly as possible.
> What's all the fuss about Signature Plastics keycaps and O-rings ?
O-rings usually rest on crossbars reinforcing the mounting stem on the underside of most OEM and Cherry profile keycaps.
At the bottom of a keystroke, they are squished between the top of the switch housing and these cross-shaped supports, absorbing some sound and shock from contact.
But keycaps made by Signature Plastics don't have those supports ... so you need to get thicker O-rings in order to fill this extra space and dampen your favorite DSA keyset !
Some people seem happy with my "Thick" O-rings underneath their DSA keycaps - but in my opinion, the "XXL" ones give a much better balance of feeling and key travel reduction.
Either way, going :
- Too thin (< 2.5mm) won't have any noticeable effect.
- Too thick (> 3mm) will stop you from being able to actuate every switch comfortably.
I don't have much experience with SA profile keycaps but /u/OssieOsbert has made some valuable discoveries over at /r/MK subreddit - following the footsteps of /u/FranksNewLiver and his attempt to dampen a fully sculpted SA PuLSE set with a combination of O-rings.
> Wouldn't using big o-rings just "convert" a mechanical keyboard to a rubber dome keyboard ?
« [...] I absolutely love the sound and feel of a board equipped with o-rings.
It feels like a rubber dome when you bottom out, but the compression and release of the spring retains that mechanical feel. To me, it incorporates the best of both worlds.
When I use a board without o-rings, it sometimes feels like I'm pushing buttons on an airplane console or something, not a keyboard. It feels like something that's designed to be purely functional, with little to no regard for ergonomics.
With o-rings installed, the soft landing of the key strokes adds a nice ergonomic touch to the keyboard. It feels like you're hitting rubber, not cold steel. The key travel reduction also helps a lot, because as you might have already guessed, I bottom out every key press. [...] »
> Why are they so expensive ?
The hardness of rubber is measured by the Shore A durometer - from 0 to 100.
The higher the number, the harder the rubber.
I chose these O-rings to be made from silicone rubber with a Shore hardness of 40A. It reflects a personal preference - acquired through research and experimentation with different hardnesses and rubber materials - for what I consider to be the "sweet spot" of softness.
These soft O-rings (in 40A durometer) will help you :
- Quiet down your keyboard.
- Eliminate almost all of the shock of bottoming out hard plastic to hard plastic.
- Minimize the fatigue in your fingers during long typing and gaming sessions.
If you want to keep a hard landing, you can get some hard O-rings (in 60-90A durometer) at a lower price but their noise dampening won't be as good as the soft ones.
> Any tips or instructions ?
It takes some time to install your O-rings so it's better to listen to some music while doing it !
# HOW TO INSTALL O-RINGS :
Let's start by removing the keycaps from your keyboard !