The CanDo Digi-Flex Thumb develops isolated finger and thumb strength, flexibility and coordination as it builds hand and forearm strength. The design allows for both left and right thumb usage. The adjustable thumb button can attach in 3 positions and rotates and reticulates. Each finger and thumb button can individually lock. Single spring design, with springs hidden inside plastic sheath. Use each button independently to exercise fingers or compress the entire unit for complete hand and forearm strengthening. Progressive