Created with super soft medical-grade siliscone, the LUÜNA period cup has special flexy-fit technology which moulds to your unique shape. Which size you should buy will depend on where your cervix sits during your period. You can check this easily by putting a finger inside your vagina, as though inserting a tampon. Keep going until you feel something firm, similar to the way the tip of your nose feels. If you can only get one finger joint in before touching your cervix, you probably have a low sitting cervix. If you can reach your knuckle, you probably have an average sitting cervix, and if you can insert your whole finger, then you probably have a high sitting cervix. Those with high sitting cervixes should usually opt for a large period cup, while those with a low cervix should usually choose a small. LUÜNA aren't just about periods. They're about community too. 10% of all purchases go towards donating period products to those in need across Asia.