A menstrual cup is a specially designed silicone or plastic cup put in the vagina to catch menstrual fluid before it leaves the body. To use the cup, you squeeze it and insert it into the vagina far enough you don’t feel it. It opens up against the walls of the vagina. To empty the cup, you squeeze the cup to separate it from the side of the vagina, carefully pull it out, pour the contents into the toilet, rinse with warm water and put it back in. There are instructions on the package and even good internet videos that explain how to use it more fully.