Specialty Archery Excalibur Lens. The Excalibur lens has been used to set and hold almost every freestyle record in the world. The Excalibur lens was designed to be used on a bow scope and coated with the best anti-reflective process available. Most other scope lenses are designed for eye glasses then adapted for scopes. Lens comes with 1 each of red and green fiber. To order the correct size of lens for your Super scope, measure the outside diameter of the scope housing.