Smaller, lighter and more portable The redesigned Yamaha Silent Brass module is smaller than a cassette tape and weighs about as much. It fits easily into a shirt pocket and can be attached to your belt. The sound from this "next generation" Yamaha Silent Brass system has been greatly improved. The "hiss" has been greatly reduced, allowing the player to hear more of himself and less noise. Simplified controls and sleeker look The new Yamaha Silent Brass module has only a volume knob and an echo switch, eliminating the unneeded extra features and making it even more affordable. Aux In jack allows an external sound source to be combined with the Yamaha Silent Brass mute or microphone signal. Play along with your favorite song and put the fun back in practicing .The input jack allows a quick and easy connection to a Yamaha Silent Brass pickup mute for practice or to a Yamaha MC-7 instrument mic for performance.