This study is testing non-medicated intravaginal rings, which are devices inserted into the vagina but don't contain any medicine. It's happening in Atlanta, GA, and is for women aged 18-49 years old who are sexually active. The trial is **randomized** (participants are randomly assigned to different groups), **open label** (everyone knows the treatment being given), and **crossover** (participants may receive different treatments in different periods). To join, you must be healthy, use non-vaginal contraception, and not participate in other research. **Key Points:** - The study requires regular visits and strict adherence to instructions. - There is no mention of compensation in the study details. - Participants should not have allergies to materials like silicone and must not have certain health conditions or be pregnant. Before joining, consult your doctor to ensure it's safe and discuss any concerns. Participants must avoid using other vaginal products and cannot join if they have recent surgeries or certain infections.