This sippy cup is a great idea, especially in the summer while trying to keep drinks cool, and appealing and keeping the child hydrated. However, there is one downfall with this cup. The insulated material seems quite heavier than that of a normal sippy cup, and the cup becomes quite heavy when filled with liquid.
The cups designs are great, almost holographic and are a delight to look at. It is nice to use them for warm milk, cold juice, or nice cool water. The temperature does keep for some time, but as for the cups begin heavy I have found that the child does not want to hold on to the cup.
They are a great quality cup - but not feasible for small children to hold on to - especially since they must tip to drink.
They have no spills or accidents, I just wish they were lighter - for the kids!