The MAM Baby Bottle Bundle includes two different sets of bottles to support your baby's feeding needs. The first set is the MAM Matte Easy Start Anti-Colic bottles that come in a 2-pack, 9 oz size with medium flow nipples designed for newborns. These bottles feature an anti-colic vent system that is clinically proven to significantly reduce colic, spit-up, burping and gas. The elongated, breast-like nipple shape facilitates an easy transition between breastfeeding and bottle feeding. These bottles also have a self-sterilizing function that allows you to sterilize them by adding 20ml of water and microwaving for 3 minutes. The second set of bottles is the MAM Easy Active 11 oz bottles that come in a 2-pack with fast flow nipples designed for babies 4 months. The nipple shape and soft texture helps 94% of babies accept them. An anti-slip texture keeps the nipple securely in baby's mouth and the leak-proof cap minimizes spills. These wider neck bottles also make cleaning easy. Together, this bottle bundle provides options to meet your growing baby's needs - from the breastfeeding-like, anti-colic bottles for newborns to the easy grip, fast flow bottles for older babies. Both sets are made from BPA and BPS-free materials for safe feeding. With nipples designed for easy acceptance and innovative features to reduce colic and make feeding easier, this bundle has everything you need to support your baby's healthy development.