Does the KONE AIMO have a removable mouse skate (ring) around the sensor, or is it plastic?

So I just got some mouse skates by Corepad.de (Skatez) and the kit comes with skates for all the main feet of the mouse, but it also comes with some circular ring skates.

Thing is, I could not seem to "remove" the ring around the sensor on the Kone Aimo. Is this plastic or is this actually removable? I made a few scratch marks on the ring trying to get it off and eventually stopped trying as I didn't want to mark it up too badly if it is indeed not removable.