Fingear
$10.00
If you've ever idly played with the scroll wheel on your mouse while bored, this is the fidget for you.
It offers smooth motion, but with a little bit of a tactile bump as it rolls on your finger. And it's a delight to watch the gears turning, almost as if it's a visual manifestation of the gears turning in your head as you try to focus on whatever it is you're trying to focus on.
Original design by besnia_darvar on Makerworld