Power Putty is most commonly used for warming up the fingers and forearms, but it is also a useful therapeutic aid for injury prevention and recovery. With a little imagination it can help work all the adductor, extensor and flexor muscles of the hands and fingers, to balance out hours spent crushing campus rungs (a reference card with suggested exercises is included).
Or just keep it handy for when you need to vent rage without harming furniture or loved ones.
Available in three resistances:
Yellow - Easy
Green - Medium
Blue - Firm
Non-toxic. May not be suitable for rubber-alergy sufferers.