The acoustic design of the Jo-Ral 1A Straight Trumpet Mute produces an exciting tonal quality with near-perfect intonation. It is made of spun aluminum, and has been tested to perform evenly in all registers. Jo-Ral mutes also feature neoprene-enhanced composite cork pads that provide extra durability. The result is a more pliable cork that grips well and doesn"t dry out, become brittle, or break off, so it lasts longer while easily accommodating fine adjustments for a perfect fit.Made of spun aluminum Neoprene-enhanced composite cork pads Near-perfect intonation