Bests & Worsts Reviews from Amazon

you can't fill them up all the way or the water over flows out of the top because the water expands. it's hard to know just how much water/liquid to put in them. I am using reverse osmosis water to fill them and I have filled them to the top and poured a little out to make sure that the water doesn't overflow which will create a water "nipple". The ice keeps cracking as well so it's not a solid round ball when I take it out of the mold. The silicone top and bottom don't stay together because the water expands so it creates an extra water ring around the ball of ice.