The ideal choice for any musical genre the Jo-Ral Copper Bottom Trombone Straight mute produces a distinct muted sound throughout the natural range of the instrument. It is free-blowing in all registers and designed to fit all tenor trombone bells. The Jo-Ral TRB-1C Copper Bottom Trombone Straight Mute made of spun aluminum and has been tested to perform evenly in all registers. Finished with a copper bottom producing a powerfully dark and rich sound. 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. Features: Crafted from lightweight spun aluminum and copper Great for that classic jazz sound Pliable neoprene-enhanced composite cork pads offer lasting durability and grip Soft felt cap for extra protection Made in the USA