The acoustic design of the Jo-Ral TPT-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.