Whether you want to show off your love for engineering or just need a handy fidget, 

Gearrings, can do it all.  Featuring two functioning gears secured between two snapfit plates with a hole for a 6mm jump ring.  You can spin the gears to your hearts content.  

May not be compatible with long hair - mine is short, so it is hard for me to test

Prints in four pieces that are easy to assemble. Not print-in-place!

More 3d printable jewelry

Check out my other 3d printable jewelry designs at EcoDad's Jewelry Designs!