I purchased this on Amazon this November, but I'm selling it because I haven't had a chance to use it. It has been opened, but it's unused. I disinfected it with a Pigeon sterilizing steam after opening it. Perfect for trying out the size! Medela Contact Nipple Shields, M size, 20mm, 2 pieces. Protects nipples during breastfeeding and supports the baby's latch. Gently supports breastfeeding. ◼︎ Medela's thin nipple shield "Contact Nipple Shield" Can be used temporarily when nipples are painful or cracked, or when the baby cannot latch properly. Made of thin, soft silicone, it is placed over the nipple before breastfeeding to protect it. There is a hole at the tip so the baby can drink breast milk from it. ◼︎ When using it for painful nipples Various causes can be considered for nipple pain and wounds, so it is important to check the cause before deciding how to deal with it. If you experience nipple pain, you can receive support related to breastfeeding, or use hydrogel pads or breast shells. If the situation does not improve, using a Contact Nipple Shield can protect the nipple while continuing direct breastfeeding. Made of very thin, soft silicone, it fits gently on skin with pain, dryness, or wounds. ◼︎ When using it for flat or inverted nipples If the mother has flat or inverted nipples, it can be difficult for the baby to latch, especially when they are small, but it doesn't mean direct breastfeeding is impossible. Inverted or flat nipples may not reach the baby's palate during breastfeeding, which may prevent the stimulation needed to trigger the sucking reflex. The Contact Nipple Shield extends the reach of the nipple and supports direct breastfeeding. The Contact Nipple Shield is tasteless. The baby will not feel an unnatural taste during use. ◼︎ How to use the Contact Nipple Shield After washing your hands with drinking water and drying them completely, hold the edge of the Contact Nipple Shield and place it in the correct position. Wetting the shield with drinking water will make it easier to stick. When attaching, make sure it fits comfortably on the nipple without a pulling sensation. Wash after each use, and sterilize once a day.