My heavy flow days are heaaaavy. Like soaking thru a tampon every 90 mins to 2 hrs. I have to have a pad on just to make sure that it catches the overflow. Flex changed my life. I love the self emptying tech with the silicone disc. I love how comfortable it is, I forget that I have my period and can go about my day. I still use a pad on my heavy days to make sure I dont have accidents, but this little thing lasts for at least 8-9 hrs for me and then I can go pee and empty it out a little. Phew! Don't ever stop making this!