Bremner Ssshhh Practice Mute for Trumpet or Cornet out-performs anything available on the market today! It gives accurate tuning throughout the range. It helps develop and open the throat muscles to give better airflow, thus improving the tone. It has an improved resistance factor, allowing you to extend practice sessions and enhances pitching and accuracy. It is made from lightweight ABS plastic which will not cause your instrument to feel any heavier when playing. This practice mute is designed to fit into all brands and models of instruments without compromising effectiveness. It helps you warm up before going on stage.