These Vital Baby Feeding Bottles were carefully designed to mimic the comfort and natural feel of breatfeeding. The innovative anti-colic valve is built into the nipple so there is no need for additional parts. The soft, wide flexible nipple prevents air ingestion during feeding which can lead to colic and discomfort. The valve also provides a smooth, vacuum-free flow rate making it easier for your baby to feed without nipple collapse or spills. The specially designed shape makes it easy to combine breast and bottle feeding and assures a comfortable grip for mom and baby. BPA Free. Sterilizer Safe. (2) 8 fl oz, 240 ml bottles each come with a slow flow nipple.