Watch Glass Beaker Cover Set, 6 Pcs Lab Watch Glasses in 150mm, 100mm, 70mm for Laboratory, Science and Chemical Experiment (150 mm x 2, 100 mm x 2, 70 mm x 2)

Showed up in perfect shape and matches my beakers well.

I use these daily. One larger one came chipped on the edge a little, but I use it anyway. They could be packed with slightly thicker foam between glasses. There were a couple of large glasses in the set anyway, so I'm not worried. The glasses are concave/convex a good amount, so liquids drip back down in the center of the beaker when heating solutions.

Work very well.Edges feel good and not sharp like my older covers.

The glasses seem fine but one of large ones was completely broken. I don't want to take the time to return it. It's just kind of disappointing.

I liked the packaging and the variety of sizes, but the glass could improve

I havent used them yet, but they appear to be exactly as advertised. They are likely tempered soda glass - fine for the intended/described use. They should NOT be directly heated - not used as container to hold something to be heated - not exposed to flame - not borosilicate. If this is news to you, you probably should not do what you're planning.

These are pretty poor quality watch glasses. They’re very fragile, and the edges are sharp. All of mine arrived scratched. I had one that shattered due to the heat of steam collecting on it. A watch glass should never be heated directly, but it definitely needs to be able to withstand indirect heat.

This is the item I didn’t know I needed! Comes in assorted sizes so I am literally covered! Totally recommend.