Lansinoh Latchassist Nipple Everter (Pack of 2) is designed to help prevent flatness from breast engorgement in the early days of breastfeeding. The nipple everter gently draws it out, making it easier for baby to latch on. Plus, it is made without BPA and BPS and is the first step to a successful experience. This feeding nipple shield comes with an insert that has detailed instructions. There are two different sizes for a correct fit. Key Features: Draws out flat nipples for an easier latch. Non-invasive, allowing baby to have direct nipple contact. Easy to use and clean. Two flange sizes included (19mm and 24mm) to ensure proper fit. BPA and BPS free. What's in the box: LatchAssist Nipple Everter bulb. 2 Flanges (19mm and 24mm).