Blue bicycle derailleur pulley and caps against a white one-speed bike chain.
Cycling themed EDC (Every Day Carry) fidget finger spinning toy with a small "606" full-ceramic derailleur bearing, measures about 2.50" across. The caps are removable so the ceramic bearing can be cleaned as needed. No oil or other forms of lubricant is needed with the full ceramic bearing...it will not rust. See image of side-by-side bearing comparison.
Great gift for the bicycling or motorcycling enthusiast.