A menstrual cup is a flexible cup or barrier worn inside the vagina during menstruation to collect menstrual fluid. Unlike tampons and pads, the cup collects menstrual fluid rather than absorbing it. They are usually made from medical grade silicone which is a safe and hypoallergenic material. Menstrual cups are more cost-efficient and environmentally friendly than tampons, as they are reusable, and can be used for up to 5-10 years. They have greater capacity than tampons, and can be emptied every 12 hours, unlike pads and tampons which require more frequent changing. A woman need only wear the one cup and clean and empty it at the end of the day rather than carrying several replacement pads or tampons. By keeping menstrual fluid away from the vaginal walls and vulva and unexposed to air, menstrual cups have less odor associated with their use than with the use of tampons or pads.