Fangrui Product Details All-round Therapy Extensor Exerciser - 1) Works As A Hand Therapy Ball (light And Medium Tensions) For Increasing Strength And Range Of Movement. 2) Exercises The Frequently Ignored Xtensormuscles To Guard Against And Help Relieve The Symptoms Of Carpal Tunnel, Arthritis And Repetitive Strain Injury. 3) Provides Basic Grip Training For Rehabbing Hands. Restore Strength And Dexterity; This Device Is Great For Ot Following Injury, Stroke Or Postoperative After Surgery; Reverse And Protect Your Hands Against Arthritis, Carpal Tunnel, Tendonitis And Occupational ; Works For Both Left And Right Hands Great Extensor Exercise For Athletes And Musicians - Completes A Performance Focused Workout For Any Serious Athlete Or Musician, By Exercising The Weakest Hand Muscles - The Extensors. Alongside Targeted Grip Training, Hand Flex Training Can Help Overall Speed, Strength And Fluidity Of Many Sports And Musical Performances - Get The Edge And Make The Decision To Add This Into Your Practice Routine Now