TheraBand Progressive Hand Trainer Refill Sheets, Wrist, Forearm, Hand Strengthener for Rock Climbing, Guitar & Piano Players, Post Surgery Rehab and Therapy, Assorted Resistance Difficulty Levels Assists patients recovering from finger, hand or wrist surgery, helps improve hand, finger, and thumb strength and mobility Allows therapists to perform the functional finger exercises against progressive elastic resistance, including pinching, opposition and prehension Hand trainers are extremely thin and designed to be used by those who struggle with basic motor function and patients with too weak of grip to use therapy putty Features more than 60 access holes that allow for numerous strength training and range of motion exercises Must be used with intro kit, this item is just the Yellow refill and does not contain the interlocking rings necessary for use