A menstrual cup is a menstrual hygiene device which is inserted into the vagina during menstruation. Its purpose is to collect menstrual fluid (blood from uterine lining) and prevent its leaking onto clothes. Menstrual cups are usually made of flexible medical grade silicone. They are shaped like a bell with a stem. The stem is used for insertion and removal. Every 4–12 hours (depending on the amount of flow), the cup is removed, emptied, rinsed, and reinserted. After each period.