MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I guess you can see the serration on the cones ?
One might call them gear teeth , they serve the purpose to give the rubber ring something to grab hold.
And NO it is nor a skate wheel , a skate wheel is to hard . The O ring is of a composition that has a magnetic polymer as part if its makeup and its hardness can be changed by the application of a modulated mag field