Cube Pessary, Sklar, 37mm Cube Pessary With Drain, #3, 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 #3, 37mm cube pessary with a dra in. It is used to treat moderate to severe cases of uterine prolapse as well as mild cystocele and rectocele. Insertion and removal of a cube pessary relies on suction to the vaginal walls and tends to be more difficult that other pessaries. This may cause patients discomfort. A cube pessary with a drain, such as this one, may be left inserted for up to a week before removal and cleaning is required. Cube pessaries without drains require daily removal and cleaning.