The Balu Bass Trombone Series Straight Mutes features a negligible air resistance design to allow the player a quiet mute that keeps the center of the sound focused, and eliminating intonation problems. In collaboration of top musicians and artists, Balu Mutes are able to provide some of the world's best mutes, including a Horn practice mute with negligible air resistance. Balu Mutes manufacturers mutes for Horn, Trumpet, Trombone, Euphonium and Tuba.