Super D Scope features a easy-change modular system. The scope has a large 2.16" opening. Clear polycarbonate housing for additional light gathering. The concentric shape still allows you to accurately center the scope in the peep. This is extremely important for getting on the target fast for a good shot. Several other distinctive features are quick changing rings which allow you to modify the lens or scope very quickly. This means the archer can have several different types of rings for various conditions and change them instantly. Optional Glow Rings and Cross Hair rings sold separately. The scope can change from right to left hand in seconds. Simply remove the thumbscrews and move the lens retaining ring to the opposite side of the scope housing. Scope rods are 10-32 heated steel. Glow Rings and Lens are sold separately.