The REXIS string provides improved power, repulsion, and durability from the innovative FRF (Fusion of Resin Filament) production process. Upgraded at the molecular level for greater elasticity, the super-solid REXIS string structure is produced by filling the gaps of ordinary multifilament string with the new, more flexible material, FORTIMO™. FORTIMO™ is developed by Mitsui Chemicals, Inc.Resin is bonded to nylon filaments by plasma on a molecular level to improve repulsion and durability. ・A perfect combination of comfort, feel, and ball-pocketing ・For players of all swing speeds looking for a soft string with added comfort