Mini Ninja Spinner 624Z bearing
My oldest daughter wanted a fidget spinner for a friend so I printed a couple - Then my two year old wanted to play with one but her hands are too small for normal spinners that take 608 bearings. I resized this one to accept 624Z spec bearings.
I take no credit for design. I only resized the Fidget Spinner (Ninja Spinner) by Q8Khajah.