Edgy and almost biting, the bubble mute offers and wonderfully distinctive sound. The acoustic design of Copper Bottom Bubble Mute Bubble Mute gives it a near perfect intonation across all registers, resounding projection, and an almost meaty buzz unmatched by any other.The Jo-Ral Copper Bottom Flugelhorn Bubble Mute has a unique shape and spun aluminum construction that give it a distinctive tone especially desirable for jazz musicians. This Jo Ral Copper Bubble Mute is made with copper to offer an even warmer sound that is excellent for solo work. 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.