The Lansinoh mOmma Feeding Bottle is designed with a patented nipple based on over 50 years of research - so you can give your baby your precious breastmilk while you are away, but have the confidence that your baby will return to your breast when you get home. The round shape is easy and comfortable for baby to hold and the wide design is easy to pour into and clean. The bottles feature a protective cover for leak-free, hygienic coverage on the go. Slow, medium and fast flow NaturalWave Peristaltic Nipples fit the bottle. Allows baby to mimic natural sucking rhythm. BPA Free. AVS - Air Ventilation System reduces intake of gas, a potential cause of colic or spit up. 100% silicone is supersoft, flexible and long lasting.