Featuring classic styling with an ergonomic shape, these eco-friendly bottles are easy to clean and assemble as well as easy to hold. Made with tempered glass, Evenflo Vented + Glass Bottles are also designed with safety in mind. This Mother Nature approved bottle feature patented Proflo™ Venting Technology. Expertly designed for easy assembly and leak-free feeding, the simple, one-piece integrated nipple and vent system means no extra parts to clean or lose. These soft silicone nipples rapidly vent, directing air bubbles into the bottle, not baby's tummy, which significantly reduces gas, colic, and fussiness. To help take the guesswork out of feeding your little one the Evenflo Vented + Glass Bottles feature molded measurement markers in both ounces and milliliters to provide an easy and accurate way to measure the volume of liquids without the risk of the measurements washing off. An added bonus is that these standard neck bottles fit many standard neck breast pumps making it easy to pump directly into the bottle for added convenience. Rest assured that the Evenflo Vented + Glass Bottles are 100% free of BPA, polycarbonates, PVC and phthalates and are made of FDA approved food grade material. Evenflo Classic Glass Bottles, on top of superior sanitizing, offer eco-friendly offer style, are recyclable and sustainable, making them a great choice for all moms... even Mother Nature. For over 90 years, Evenflo has provided proven breastfeeding, infant and toddler feeding products that support parents and baby throughout their journey together. An iconic classic with an ergonomic, easy-to-hold twist shape! Mother Nature Approved! Tempered glass is eco-friendly, recyclable and sustainable Proflo™ 1-piece, integrated venting technology helps reduce the potential for gas, colic and fussiness Expertly designed for easy cleaning, assembly and leak-free feeding Pump directly into glass bottles - compatible with most standard neck breast pumps