The v-ring is a birth control device shaped like the uterine cavity that prevents the fertilized egg from implanting. The v-ring is usually made of stainless steel with a silicone rubber tube on the outside and a relatively large area of copper wire in the horizontal and diagonal arms, similar to a miniature chain. v-ring contraception is based on the principle that the copper ions inside the ring alter the cervical mucus, preventing fertilization of the egg. The v-ring is different from other forms of birth control in that it does not have a fixed ring body as a support, which allows for greater freedom of movement and maximizes fit in the uterine cavity. In addition, the v-ring has a relatively low rate of dislodgement in clinical use, but a relatively high rate of bleeding, with both good and bad aspects. Women are advised to make judgment on the choice of birth control ring according to their own actual situation as well as the doctor’s recommendation.