The TrumCor Copper Bottom Aluminum Trumpet Straight Mute has a unique design that creates a superior fit, exceptional intonation, and instant response. A combination of aluminum alloys produces a brilliant sound, and the copper bottom adds a touch of richness to the sound in every register. TrumCor Mutes are carefully crafted from selected grades of materials. Each mute is designed to produce a muted tone that is in tune, vibrant, warm, and responsive. TrumCor Mutes blend well with other instruments and preserve the unique sound quality of each instrument in all registers and at all dynamics.