Reusable menstrual cups are a sustainable and cost-effective alternative to disposable menstrual products. They are made of medical-grade silicone and are designed to be inserted into the vagina to collect menstrual fluid. They are easy to use, comfortable, and can be reused for up to 10 years.
From Wikipedia
A menstrual cup is a menstrual hygiene device which is inserted into the vagina during menstruation. Its purpose is to collect menstrual fluid. Menstrual cups are made of elastomers. A properly fitting menstrual cup seals against the vaginal walls, so tilting and inverting the body will not cause it to leak. It is impermeable and collects menstrual fluid, unlike tampons and menstrual pads, which absorb it.