The Jo-Ral 4A Trumpet Bucket Mute features aluminum construction. The acoustic design of Jo-Ral trumpet mutes creates an exciting tonal quality that results in near-perfect intonation. Jo-Ral 4A Bucket Mutes are made of spun aluminum and have been tested to perform evenly in all registers. The trumpet bucket mute provides a unique haunting sound that is both deep and slightly hollow. This is a specialized mute for a distinctive sound.