Do different brand sizes vary even though they are the same size?
Yes. Every cup design is different in diameter, size, length and more according to the brand of cup. You may opt for a small size in one brand and buy a new cup in s small size in another brand and notice huge differences. Not all menstrual cups are made alike, it is best that when you find an ideal size in a cup you stick with that cup or look for a similar cup that offers the same specs and size criteria.