Eco-Friendly Baby Bottle Contains Two Bottles with Level 1 Nipples Safe for Your Baby. Safe for Mother Earth. Eco Classic Babies Know BestDesigned to Reduce Colic, Gas and Spit UpBabies Control Milk Flow-Like Nature IntendedHelps Minimize Middle-Ear Infections Free from BPA Phthalates & PVC Recommended by: Dr. GreeneActiveFlow Nature in the Hands of your BabyActiveFlow bottles feature a silicone valve that allows milk to flow only when a baby suckles and lets babies control milk flow according to their changing needs - like breastfeeding.In addition, a patented venting system reduces pressure during feeding and is designed to help ease painful colic symptoms.Soft Silicone Nipples Available in 5 flow rates from Newborn to 18 months.Designed to Help Ease Colic Symptoms Silicone valve minimizes air ingestion and helps reduce gas and spit up. Built-in vents reduce pressure and the risk of middle-ear infections.Ideal for Breast and Bottle Combination Milk flow begins only when baby suckles. Flow rate controlled by baby - just like breastfeeding.Long Lasting Safe Plastic Eco-friendly, 100% free of BPA, phthalates and PVC.Top rack dishwasher safe. No leaksMicrowave safe.