Five-component matrix system. Universal ring is made from a proprietary resin material that is autoclavable up to 5 times. Ring has exceptional strength for optimal separation force and stability to deliver perfect, tight, interproximal contacts. Unlike Tofflemire retainers that are difficult to position, leave poor contacts, and cause patient discomfort, this system is easy to use and achieves accurate Class 2 composite restorations with smooth contours.