Colorful Office Thinking Hand Boiler, Glass Science Energy Transfer, Children Science Experiment, Love Birds Color Meter Hand Boiler, 4 Pcs (Red&GreenBlue&Purple) by C&H Solutions®

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.

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.

The kids loved this, but they are very fragile and can break fairly easily if a child holds it too tightly. So just make sure they are gentle with them.

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.

Fun to see in action

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.

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.

Students loved these in science class during Thermal Energy/heat transfer unit. Recommend. *they are delicate, but grade 8 kids handled them well with lots of reminders :)