Awesome! Delivered no damage everything as pictured.

Brings back memories. These hand boilers were very popular decades ago. Low tech device that needs just body heat to work. Fun, but glass is a little fragile, so not for rough handling or young children. Given to my niece’s children to introduce them to a bit of nostalgia.

I had previously purchased one random hand boiler and decided to purchase the entire set because they are pretty cool to play with although they look so fragile. (They are not as fragile as you would think as mine has been knocked over on more than one occasion and survived!) I was disappointed, however, when I unpacked them and found that the green one was broken. They are very well packed so I'm not sure how it got broke, but I missed the time frame to return:(

They come in a pack of four pretty colors. Concept is neat to teach science. Three of them work well, but one, while the glass is still intact, still does not work. Not worth the hassle to return all four, as there is no option to get a replacement for just one.

These devices demonstrate some very clear principals of thermodynamics and are very interesting at the same time. When you hold them in the palms of your hand, just the heat from your hand causes the fluid to percolate up to the top and bubble up there continuously. It works spectacularly.I got the set of four and they were packaged well. They are relatively fragile blown glass and thus require good packing. All four arrived safe.

Ordered four and all arrived intact. I was not sure if they would from other reviews. Kids and girlfriend liked them, but the glass is thin, and I could see them being broken easy if your not delicate with them.

All the hand boilers arrived individually boxed and none were broken. They are delicate, but even my 6yo can hold them with supervision. These were the big hit at Christmas. The colors are all beautiful and along with teaching about heat/energy, they simply look like beautiful art pieces. You will not be disappointed.

Fun product at nice price. Make great gifts. Nice to know what colors you get. Good quality but very fragile and some were broken. Amazon immediately replaced without me having to make a return. I first ordered for adult bible study class, the ladies loved them. Made a big hit at Christmas. Have already ordered some more, should arrive today.

First of all, I ordered the 4 pack and all 4 arrived intact. I got one of each color/design: blue, green, red, and purple.I use these to demonstrate thermal expansion and the concept of boiling points in my junior high science classroom. The students love them, but I have yet to find a way that I can keep them in my "museum" (book shelf full of cool, hands-on science things for the students to explore) without the hand boilers getting broken within a few weeks. They will break with rough handling (you don't need to squeeze!) and the tops are more fragile than the base, but if you are careful with them - always put them down on a level surface! - they can last for years.

Great handboiler very amusing (but) beware of handling it or squeezing it hard because it’s very easy to break especially in the hands of children.