A product for the woman who does not want to take a medical/chemical produced pill year after year in case of what the consequences of long term usage might do to ones body. That being said, Persona requires an "ordnung muss sein" personality. You have to check in 8 eight times a month with test sticks and when not in a steady realtionship - use rubber. Been using it for 10 years and no problems.
Ingrid, Norway