These transitional nipples turn your Comotomo baby bottle into a sippy cup straw cup or a soft food dispenser. These nipples are compatible with the Comotomo bottles sizes Biz and 8 ounces. All components are made from a non-toxic food-grade silicone and polypropylene and they are BPA Phthalates Latex and Lead Free. The ANPEI products are independently tested to meet or exceed the U.S. Consumer Product Safety Commission requirements. The nipples are designed to be leak-proof and heat-resistant for 120°C/248°F for effective mixing and transportation.