Shields are ideal for short term latch on issues with premature, small, or ill infant, flat or inverted nipples, tongue or lip tie, or overactive let-down. Nipple shields are 24mm size with a protective case for hygienic & convenient storage. Are made of 100% super soft silicone that provides maximum breast and nipple comfort. Sanitize the nipple shield by boiling in water for 10 minutes before first use. Lansinoh pads have been trusted for decades by both mothers and healthcare professionals to provide safe, effective breastfeeding support.