This is Vaginal ring for stopping pregnancy...see it

 The ring is inserted into the vagina and provides contraception protection. Leaving the ring in for three weeks slowly releases hormones into the body, mainly vaginally administered estrogens and/or progestogens (a group of hormones including progesterone). These hormones stop ovulation and thicken the cervical mucus, creating a barrier preventing sperm from fertilizing an egg. Worn continuously for three weeks followed by a week off, each vaginal ring provides one month of birth control. Several vaginal ring products are currently available, including:

Estring - a low-dose estradiol-releasing ring, manufactured from silicone elastomer, for the treatment of vaginal atrophy (atrophic vaginitis). Femring - a low-dose estradiol-acetate releasing ring, manufactured from silicone elastomer, for the relief of hot flashes and vaginal atrophy associated with menopause.                     NuvaRing - a low-dose contraceptive vaginal ring, manufactured from poly(ethylene-co-vinyl acetate), and releasing etonogestrel (a progestin)ethinyl estradiol (an estrogen). Progering, containing progesterone as a sole ingredient, is available only in Chile and Peru.