The Beastmaster  concept was a revolution, and was one of the most important rod successes in Shimano history. One limitaion of the original material, however, was the weight, which was heavier than conventional carbon,  thought with enormous resilience. With the discovery of biofibre, the Beastmaster spinning range has overcome this limitation. Now these rods are extremely light and have a fast action, yet retain the same unbelievable strength.