DO NOT PURCHASE THIS PRODUCT! Terrible design: too big/heavy, mouth piece is too thick and causes dripping after attempting to drink from it. The cup also spills from the lid other than the spout. Company will not allow you to return the product once it's used. (So tell me, how would you know if it works unless you use it?)A good company would stand behind their product; this one does not.I will never purchase from this company again.