This new mute is designed by Shinji Hamanaga, the inventor of the Yamaha Silent Brass System. The Warm-Up is so small that it fits completely inside the bell, allowing you to store it inside the flare when the horn is in the case. Incredibly lightweight at 60g, you hardly notice it's there. It plays well throughout the entire range, and is very quite. Though pricey, it's much more comfortable that a larger mute to use for long periods of practice.