The Evenflo Feeding Classic Bottle delivers a twist on an iconic, classic design. The unique, ergonomic shape is lightweight and easy-to-hold, making feeding time comfortable for both you and your baby. The included Classic Slow Flow Nipples are 100percent silicone and feature micro air vents to help prevent nipple collapse. The nipple has a gradual transition between nipple length and base to allow your baby to maintain their latch. Made from BPA-free polypropylene, the Classic Bottles have molded measurement markers in both ounces and milliliters to provide an easy and accurate way to measure the volume of liquid. These dishwasher-safe bottles (top rack only) are compatible with all Evenflo Feeding breast pumps, as well as most other standard neck breast pump brands. The bottles and nipples are 100percent free of BPA, polycarbonates, PVC and phthalates, and are also made of FDA-approved food grade material.