Now your child can drink from a straw like the big kids! This replacement straw kit is designed to make the transition to upright straw drinking easier. Like many of our silicone spouts, the Flex Straw™ replacement kit features a No-Spill™ Touch-Flo™ valve that opens instantly with a small amount of pressure, making it simple to drink from. When the pressure is released, the straw closes ensuring a leak resistant cup. This unique valve originated on Nûby™ cups and is endorsed by pediatric dentists all over the world because it encourages natural drinking and oral development. And since it's from Nûby™, you can be assured that it is BPA Free!