Made of high quality pp, healthy and safe.It works better with olive oil or cream.Corrective nipple depression,natural help with inverted or flat nipples,helping your nipple regain confidence.Clinically proven to help with inverted or flat nipplesAnd contains a replacement air valve.Suitable for pregnant women, mothers, etc. Attention3 hours a day.When wearing a nipple appliance, you can apply some skin cream around the nipple to increase the suction of the appliance.Because the degree of nipple depression is different, the correction time is generally different, it takes about 2-3 months, please be patient.