Like all Shimano reels, Corvalus is evaluated to meet the same standards as their top-of-the-line models. With smoothness, durability and functionality inherent in the design, all one has to do is focus on the fish being pursued. The Variable Brake system uses centrifugal force to control the cast increasing distance and adjustability. The Super Stopper is a one way roller bearing that eliminates backplay providing solid hooksets. All metal frame and sideplates.