I sit water bottles inside
these cubes.
The cubes are sold with fluffy bedding inside which you should throw away because it's dangerous, but the cube itself is fine.
The Savic bottles (smallest size) fit best. Classic bottles (75ml or 150ml) fit too but not as snugly.
Depending on what type of hamster you have you might have to sit the cube on top of something else so it's the right height for drinking.