S for small and more importantly... Screw in Stabilizers! These are intentionally thinner than your normal o-rings to allow the use of the screw in stabs on the backspace and spacebar.
PLEASE READ THE CHART BELOW FIRST!
Please only buy this o-ring if you are using screw in stabilizers for your 60% keyboard. There is also a chart for you to see if your board is on our checked list. If it is not on our chart, we do not recommend buying it, and you are buying at your own risk.
If you have a keyboard that isn't on our list, but you want to add it, please contact us: firstname.lastname@example.org