A. One Size Fits Most - By covering the nipples and using pressure to suction inverted flat nipples, a suitable shape for breastfeeding is created. B. WEARABLE EVERY TIME - The size is similar to that of the nipple. It does not affect the appearance after wearing when wearing a loose bra and other clothes. C. Packs In PP Case - A set (2 pairs) of pp boxes, with a storage box, easy to carry and store for daily life and travel. When one pair is cleaned, another one can be used at the moment. D. HYGIENE AND HEALTH - Using soft medical silicone material which can be sterilized in microwave oven. It reduces the load on the skin and is comfortable to use. E. ADJUSTABLE - Flexible adjustment of the force of attraction by compression. Easily find a suitable fit for your strength.