This is the perfect mug for a scientist, nerd, geek, teacher, parent, or gifted student... actually... pretty much everyone. When coffee or any other dark-colored drink is added, the graduations become even more visible. Whether you are enjoying a cup of espresso in the AM or some liquor on the rocks in the PM, you're going to be satisfied.
There are other beaker mugs. We tried them all. Some of them may even be. GASP, less expensive. But this is the one you want. It is lab quality (seriously) and will last.
Note: Wash thoroughly before use.
Eisco Labs Borosilicate glass has the following heat tolerances: Strain Point -515°C | Annealing Point 565°C | Softening Point 820°C.