This set of pieces can be used to "adapt" M10 nuts as counterweights and use them in spinner frames that were designed to have 608 bearings as counterweights.

You will find a piece that works as the adapter piece to insert a M10 nut in a hole made for 608 bearings, useful to put M10 counterweights in a spinner. This piece has an hexagonal shape for the nut to fit inside it, and an outer diameter matching the 608 bearing.

Also you will find a M10 nut cap for fidget spinner, it can be used to cover M10 nuts when they are used as counterweights in your fidget spinner. This helps improving the visual look of the spinner. The caps can be screwed on each side of the nut. 

Finally, there are tall center caps (male and female) for spinner. Specially useful if you are using caps to cover the counterweights, thus needing a taller center cap to be able to spin the spinner over a surface (like a table).

This object was made in Tinkercad. https://www.tinkercad.com/things/fXQnxZxoq8O