omg i do that with scissors! Anything with an uneven mass distribution that can be twirled in my hand... yeah i am totally doing that!

For those looking for one of these: google bike chain spinner / fidget or amazon link. I just punched 'gear fidget' into google and clicked on image search and there are several people who make these. As well, I have no doubt there are some guys (I'm under no illusions: as an autistic lady, I know I'm trapped in endless poverty but not everyone is) with 3d printers: you can make them. There are dozens of different fidgets available for 3d printing, although they won't have the same satisfying pulling sensation as you whip it around because 3d printing can't really make plastic foam or variations in material density, but hey... toys are toys right? :)