Reusable menstrual cloths are an eco-friendly and cost-effective alternative to disposable menstrual products. They are made from soft, absorbent materials that can be washed and reused for up to five years. They are comfortable, discreet, and come in a variety of colors and styles.
From Wikipedia
Cloth menstrual pads are cloth pads worn in the underwear to collect menstrual fluid. They are a type of reusable menstrual hygiene product, and are an alternative to disposable sanitary napkins or to menstrual cups. Because they can be reused, they are generally less expensive than disposable pads over time, and reduce the amount of waste produced.