If your intent is to use them in a water-bottle this could be just the thing to get ice just the right size. Very small unit, will not make many ice balls but will fit in tiny ice boxes of RVs and small coolers. The directions are a little misleading, it should say fill to the top of the bumps, or one quarter full. before laying flat to freeze. But maybe if I got it, it will be self explanatory to other users. I don't know if this product contains BPA, the toxic chemical in plastics that's been in the news of late. made of poly-pro, I have some thermal undies made of the same stuff!