Designed by a doctor to strengthen and balance the muscles of the hand, wrist and forearm. Super-effective for rehab or prevention of climbing-related finger, wrist and elbow injuries. Exercises the hand through a full, natural range of motion. An essential tool for serious climbers. Includes step-by-step instructions. 3 firmnesses available: Soft (blue), Regular (red) and Hard (orange) Sold individually or as 3 pack of all versions: Soft, Medium and Hard