SET OF 4 - we attempted to use these and my LO didn’t like them. They have been washed and sterilized. Was used with formula. No cracks or chips in the bottles. The nipple size is : 2 The Philips Avent Natural Glass Bottle is the most natural way to bottle feed. The wide, breast-shaped nipple promotes natural latch-on so you can easily combine breastfeeding and bottle feeding, and the unique comfort petals provide an extra soft, flexible nipple without nipple collapse. In addition, the anti-colic slow-flow nipple helps newborns feed comfortably and easily, and the ergonomic shape makes it comfortable for parents to hold and easy for small fingers to grasp. Assembly is simple, with only a few parts, and the wide bottle neck makes filling and cleaning easy. This Natural Philips Avent bottle is made from BPA Free glass, and works with all nipples and caps from the Natural line.