Blue Colored Ferrofluid in a Bottle Display - Magnetic Ferrofluid Decorative Magnet - Science Kit - 1 Count - Glass Bottle

It works and reacts to the magent just like videos seen online. It is a little small maybe only the size of my palm, but lots of fun ti play with i could see it being a choking hazard for very small children but loads of fun for anyone else great buy quick delivery and great present for $20

It's just so fascinating to look at and play with. It makes a really great desk decoration too

The good: fun toy and great conversation starter. Got it for my desk at work so folks can fidget during meetings and such. Accomplishes this purpose well. Cons: Small! Size of hotel shampoo bottle. Also, rust is building up pretty quick. After 3 days, the liquid has a pink hue. Bonus: A back-up Sorry piece in case you’ve lost one over the years.

Know that the vessel the fluid is in is not tempered glass. It breaks very easily.

The clear liquid was was very misty in the package I recieved. But overall great item.

This is SO COOL! I bought it for my boyfriend but i am honestly thinking of keeping it for myself! Works as advertised and comes with a magnet incase you dont have one. The ferrofluid has a nice blue and purple shimmer and always responds to the magnet!

Whether you're a magnet enthusiast like myself or just casually interested in magnets, this magnetic ferrofluid is well worth the purchase. Note that it is not technically magnetic itself, but rather is attracted to magnets, an important distinction.

I ordered 10 of these to share with my chemistry club. I wanted to let my students play with ferrofluid without having to deal with the mess. If you just buy ferrofluid by itself, it tends stain everything that it touches. All of the items came in good condition; the vials were intact, and there was no sign of leakage. The ferrofluid was very responsive to included magnet and did not stain the glass. There is a very thin layer of ferrofluid that sits on the very top of the liquid but I suspect that is unavoidable. I should note that the magnet included was not the shiny hematite "stone" show in the product pictures, but rather a black pushpin magnet. The cap under the plastic seal must be made of a ferromagnetic material so you can just store the magnet by sticking it on the cap. The ferrofluid wasn't quite as blue as I had hoped but rather a very dark blue/black. If you have another magnet, you can get the fluid to flow from one magnet to the other and do other "tricks" but this is a small container (roughly 2.75 in x 0.8 in x 0.8 in). Overall, I was pleased with my purchase.