Berp Brass Buzzing Practice Tool By using a Berp and attaching the mouthpiece next to the mouthpiece, you can hold the instrument and buzz just as you would when playing a real instrument. In addition, by moving the dial up and down to open and close multiple holes, you can adjust the breath resistance (pressure) when buzzing. In addition, by holding the instrument, you can perform fingering and sliding techniques at the same time, making it an effective tool for practicing and warming up. BERP Buzzing Practice Tool for Trombone and Euphonium (For small/medium tubes) Practice buzzing with the mouthpiece while moving the slide and fingering. You can practice in the same posture, correct position and angle as when playing normally, and you can also adjust the resistance. *Product images are for illustrative purposes only. In addition, there may be some rattling due to compatibility with the instrument or mouthpiece or individual differences.