The present invention provides compounds, compositions thereof, and methods of using the same. Therefore, no bubble remains in an ink flow passage, and no discharge failure is caused. 5 to about 15 percent chromium, from about 3 to about 10 percent cobalt, from about 2 to about 5 percent tungsten, from 0 to about 0. As the strings of the tennis racket are impacted by a ball, the metal ball is activated by the impact force to vibrate at a high frequency in the cell of the elastomer.