Designed for fabricating crown & bridge working models with sectioned, removable dies. Unique rectangular dual-pin design gives added stability while maintaining an easy-to-use pinning system. Like the original Mainstay™, Mainstay™ II utilizes a protective sleeve and rubber end cap. Its protective sleeve and tapered dual-pin design prevent reverse placement of sectioned dies. In addition, the protective sleeve grips the dowel pin, creating positive indexing and protecting the base-stone material from abrasion. This eliminates the base stone from becoming abraded, which can alter the fit of the die, causing costly rework.