These are my FAVORITE! These valves are perfect because they are super simple to clean and the are at a great price. I have never had a problem with mold in my experience. And the piece is super easy to pop in and out of the cup. I will definetely continue to buy these.
These work great if treated nicely, and let's face it toddlers are rough. If my child even just dropped the cup the valve would pop out and juice would go everywhere. Finding a "spill proof" or "leak proof" anything for a toddler seems next to impossible and when you find one that claims to be, you end up disappointed.
These are my favorite type of cups for toddlers! The valves are easy to clean and don't get mildew in them like other ones do. Easy to pop off and put in the utensil basket in the dishwasher. These are spill proof and perfect for taking on the go!