The National Institute of Child Health and Human Development (NICHD) has a mission to develop safe and effective contraceptives for women. With the increased incidence of STIs there has been considerable effort to develop dual products that prevent STI transmission. Condoms remain the best protection for prevention of STI including HIV. Male condoms are effective when used correctly and consistently but typical use contraceptive failure is high. There is an advantage to having a product that is controlled by the female and can be applied prior to sexual activity. In addition, the female condom provides better protection of the labial surface which is an important factor for some STIs. PATH has used an iterative process to improve the functionality and acceptability of the new condom and a small comparative study indicated that women preferred the PATH condom to the other available female condoms. FDA approval of the product will require demonstration of contraceptive eficacy in 200 women who complete 6 months of use. The typical dropout rate in a barrier study is 50-60%. Thus we propose to enroll 500 women in order to achieve the goal of 200 women completing 6 months.