Nipple shields are designed to address common breastfeeding issues such as flat or inverted nipples, as well as those experiencing difficulty with breastfeeding, pain and overproduction. Nipple shields are made of 100% clear, food-grade soft silicone that is ultra-soft, lightweight and resilient. The material is BPA-free and non-toxic to humans. Split design,Removable built-in valve,Longer nipples make it easier for baby to get milk while reducing mom's pain. Built-in valve fully wrapped nipple, not afraid of baby pulling. Airtight negative pressure design, the more the baby pulls, the tighter the fit. Nipple shields have a petal design that conforms to the curves of the body. Easier to fix. Its imitation areola bump design, so that the baby and the areola more realistic contact. Specification: Batteries required: No Item Weight: 3.17 ounces Package List 2 x Nipple Shields 2 x Box Tips: Nipple protection cover if torn or old aging phenomenon please replace in time. If you have any questions during use, please feel free to contact us, we will serve you wholeheartedly. Nipple shields are designed to address common breastfeeding issues such as flat or inverted nipples, as well as those experiencing difficulty with breastfeeding, pain and overproduction. Nipple shields are made of 100% clear, food-grade soft silicone that is ultra-soft, lightweight and resilient. The material is BPA-free and non-toxic to humans. Split design,Removable built-in valve,Longer nipples make it easier for baby to get milk while reducing mom's pain. Built-in valve fully wrapped nipple, not afraid of baby pulling. Airtight negative pressure design, the more the baby pulls, the tighter the fit. Nipple shields have a petal design that conforms to the curves of the body. Easier to fix. Its imitation areola bump design, so that the baby and the areola more realistic contact.