The blue-grey color is lighter than shown on the product page. 2 wooden dowels did not line up, making the job a lot more work. if you are rocking side to side your doing it wrong duh! using this for deep tissue massage and not as a medicine ball. Some feel heavier and slower, and some feel incredibly nimble. I suppose those would be called industrial grade. These aren?t painful. It has a huge long lasting battery. They fit awesome and are cozy underfoot. Especially since there isnt any feedback of your mic to the ear phones.