24-millimeter Shield Maiden nipple guards are manufactured from lab-tested, food-safe silicone that feels velvety on the side your baby interacts with, while the side facing the mother is smooth to ensure secure adherence. Color-changing quality: Nipples are colorless when they're at body temperature but change back to their original color once you remove them from your breasts. Two nipple guards are accompanied by a carrying case and a booklet by renowned lactation consultant Katie Dunning. FSA, HSA and HRA reimbursable.