Yonex Exbolt 63 0.63mm Badminton is a forged fiber string which allows up to 24% more durability. The characteristics of Exbolt are enhanced repulsion, durability and hitting sound.Forged Fiber is a high intermolecular bonding force which increases strength by removing any impurities during manufacture and then stretches it many times over the original material.Exbolt is a resilient string with a comfortable feel. Length: 200m / 656feetGauge: 0.63mmColour: White, Yellow or Black