Bought this for my fidgety kid and she loves them. The plastic things move smoothly up and down. The only reason I gave them three stars is that the pencils are not a traditional size. So, when these pencils are done, you can't move the spinner to a typical Tyconderoga or other pencil because they are too big and fall right down. I'm going to try to use a rubber hair band under them so we'll see. If you buy these understand you basically have to throw them away once these pencils are done, which is a waste.

Good for fidgeters, but they are larger and heavier than you might expect once you actually have them in your hands. They also make the pencil feel top-heavy but I suppose they have to use thick enough plastic to make them durable. I received the exact four shown in the picture.
The first one snaps back and forth and slides up and down.
The second is a nut on a threaded post (this is my favorite).
The third loosely fits over some large bumps (I like this one the least).
The last has a wing nut on a threaded post (it's probably the heaviest).

They fit snuggly on a standard pencil but can be removed once you've worn the pencil out.

I decided to order a larger pack because the picture showed the 6 count with two wingnut fidget. Upon receiving the pack I was disappointed it only included one. Also, all though most people, in the question section, said they were removable and able to be put on different pencils, I have been unable to pry these off the included pencils. It seems like it is super glued on. The hexagon and square shaped fidgets are just very loose and doesn't provide any resistance and pretty ineffective. Overall it's the first pencil product that is beyond just sensory bumps and that is helpful for an ADHD child who tends to bang and bounce the pencil and throw pencils to provide an outlet for his hand impulsivity. There is room for improvement with two of the fidgets and when you order more than the base set of 4, you should get an equal amount of each type of fidget to improve customer satisfaction.

My 9 year old tends to finish his work at school quickly and gets bored when he is done and has nothing to do. He used to get in trouble for disturbing others, so I thought I would give these a try. Of course I had to explain to him that they can't distract others from their work and that he can play with them in his desk just to keep his little hands busy. I let his teacher know he has them so she would know what he is doing. I asked his teacher about how they are working at school and she said they are amazing, and now more of the kids have them because my son explained them to everyone HAHA. There are 2 that make clicky noises so we just keep those at home for him to use when doing homework. I highly recommend these for kids who have a hard time focusing or who just need to keep their little hands busy when they finish their work.

My son (9 yrs) likes all of them... so I'm happy. I personally find the 2 screw type ones to be most useful and interactive. The other two are more loose (and noisy) but he likes them all. He takes them off his pencil at recess and plays with another boy with them pretending they are various things (I can't remember what at the moment!) They can come off and then back onto the pencil. Just don't try to remove it from the eraser side however, as I did, and end up pulling the metal thing clean off the pencil! Had to superglue it back on to fix the pencil.