Plastic box for digi-flex multi hand exerciser, holds 4 buttons the digi-flex multi hand exerciser develops isolated finger strength, flexibility and coordination. Interchangeable finger buttons make the multi a truly versatile exerciser. Use each button independently to exercise fingers or compress the entire unit for complete hand and forearm strengthening. Change resistance for any finger by changing the finger button. Finger buttons snap into base with ease. Base has padded ergonomic palm bar. There are 8 levels of finger buttons available: tan (xx-light), yellow (x-light), red (light), green (medium), blue (heavy), black (x-heavy), silver (xx-heavy), gold (xxx-heavy). buttons sold separately. clinic hand therapy and home exerciser kits, as well as individual components available. Empty plastic box – for 4 buttons.