The CanDo® Digi-Flex® develops isolated finger strength, flexibility and coordination as it builds hand and forearm strength. Use each button independently to exercise fingers or compress the entire unit for complete hand and forearm strengthening. Comes with illustrated manual. Develops isolated finger strength, flexibility, and coordination. Stronger fingers cannot compensate for weaker ones. Progressive color-coded resistance gives patient positive feedback. Also builds hand and forearm strength. set of 5 (yellow, red, green, blue, black), no rack.