I'm not much of a fidgeter myself, but I love magnets and I love to play with them, so I designed this fidget toy which allows you to insert different amounts of 4mm x 1.5 magnets in order to make your fidget toy as interesting or as unique as you like.

the 2 bottom layers maintain the magnets in their place, but there's a small orifice which lets you eject the magnets easily, they friction fit if they're set to attract each other, but my guess is you'll need the caps if you set them to repel each other. There's room for 8 magnets or 7 magnets and the cap, although the sides are very unlikely to split apart under normal use, I include a wedge for each side, so they'll need to catastrophically come apart.

My test has less than maximum attracting magnets and it's quite stiff, I'm going to disassemble it and start with 1 magnet per slot and see how it feels. I'll give opposing magnets a try as well and see if it feels better, also a mix of opposing and attracting magnets might be and interesting experiment.

1 Row of attracting magnets feels quite nice, it clicks and it rolls for a short period of time like a rusty bearing.

1 Row of opposing magnets feels the same as attracting ones, but the 2 sides don't fit symetrically which is a big nope.

Still to experiment is different amount of magnets to make it click at different strengths and maybe opposing so it will be unstable in a specific position.

The one I'm sticking with is the following (1+, 2+, 3+, 4+ 5+, 1-, 2-, 3-, 4-, 5-) (1+, 2+, 3+, 4+, 5+, 5-, 4-, 3-, 2-, 1-) It fluctuates in strength kind of like a sine wave.