The HandMaster Plus™ hand exerciser helps strengthen hand muscles. The HandMaster Plus™ can be used to treat carpal tunnel syndrome, tennis elbow, golfer's elbow, RSI's (repetitive stress injuries), tendonitis, DeQuervains' syndrome, Dupuytren's contracture, osteoarthritis, osteoporosis, stroke, neuropathy, post-surgical rehabilitation, sprain/dislocation/fracture rehabilitation, subluxation and adhesion, and circulatory concerns. This exerciser combines flexion and extension. Instructions included. There are 3 levels of firmness available: soft (purple ball, yellow cord), medium (red ball, black cord), firm (orange ball, gray cord).