Meet the Thunder Ball: a finger and grip trainer that helps you strengthen your hand for serious competitions. It is a 4″ hollow steel ball with a tough powder coated finish. It has a smooth finish to test your finger strength. You can use a carabiner to attach the Thunder Ball to a pulley machine.
More gadgets like this ➡️ : here
*some of our articles have aff links. Please read our disclaimer on how we fund Exxponent.
