Shorter and wider than narrow neck bottles, our wide mouth design. Accordion Flex peristaltic silicone vented nipple with a stretch and flex action that creates the ideal bottle feeding conditions and reduces the chance of of gas or colic. Seal tight, leak-proof and color coordinated bottle ring that eliminates drippy messes during feeding. Stainless steel lid to keep the nipple clean and doubles as a 2oz measuring cup for perfect breast milk measuring and preparing formula