they are stage 2 nipples, 5 count, & 8 oz each, used a couple of times and sterilized, they are good for alternating with breastfeeding and formula feeding without giving your baby nipple confusion, you can purchase sippy cup attachments as well as handles also make them very useful. it's a healthy alternative to plastic bottles as these are food grade silicon. very easy to use and clean. has 2 large vents to prevent formula bubbles causing colic. my baby due to tongue tie was not able to use these. smoke and pet free home. always sterilize before using. thanks