Ring Pessary, Sklar, 2 3/4 in. Ring Pessary With Support, Size #4, Non-Sterile, Silicone, Latex Free. Pessaries are OB/GYN products used for the non-surgical management of certain gynecologic conditions. There are a several types of pessaries, each designed and used for a specific treatment. This product is a #4, 2-3/4 inch ring pessary with support. Similar to a donut pessary, a ring pessary is most commonly used for the treatment of uterine prolapse. A ring pessary is often used for mild prolapse. If the prolapse is moderate, a donut pessary is often used. If a prolapse is due to a cystocele, a ring pessary with support is often the preferred treatment option.