These cubes are enough for my group to use in the Science Olympiad. However, the previous reviewer was right. The stones are slightly scratched and not labeled themselves (there is a key on the box, but if your students mix them up they won't tell the difference unless you check them). The tray that holds the dice is cheap and flimsy and probably won't last long. The box is also cheap and flimsy. The latch is easy to break and I think I need to glue the box together with super glue or gorilla glue in a short time as well. keep them, keep looking.