Use Kiinde Twist Sippy Tops and Straw Tops to transform your Twist Pouches (sold separately) into sippy cups or straw cups for your little one! As a part of the Kiinde Twist Breastmilk Feeding System, Sippy Tops and Straw Tops help you transition from late stage infant feeding to transitional feeding and onto solids and purees. Soft silicone valves prevent leakage and allow flow only when your little one is sucking (not when the pouches are in your bag or on your floor), making them ideal for feeding on the go. Sippy Tops twist-lock tightly onto Twist Pouches, so even the strongest little ones won't be able to pull off these caps. For a better grip, Twist Pouches can be snapped into Kiinde's Squeeze Natural Feeding bottles. This set includes 3 Sippy Tops with leak-proof caps, 3 optional straw attachments, and a cleaning brush.