CUP M Recommended for women under the age of 30 and who have never delivered vaginally. If under the age of 30 and have delivered by caesarean section, consider using the smaller cup size.
CUP L Recommended for women who have delivered vaginally and for women age 30 and over. Because as we age and after having a baby our hips naturally widen and the vaginal muscles lose elasticity. If you are under the age of 30 and have not had a vaginal birth, but do have a very high level of menstrual flow, you may wish to select a larger cup.