The BERP (Buzz Extension and Resistance Piece) clamps firmly onto the open end of the receiver, with the mouthpiece removed. The clamp is designed to tighten around a round, hex or convex shaped opening. On some receivers which have an oversize ring at the opening, it may be necessary to push the clamp past that before tightening down. Most people prefer the Ultimate BERP to be lined up parallel to the receiver at the "three o'clock" position. You may experiment with it in other positions to determine what is best for you. Once the BERP is firmly attached, you can then alternate easily between buzzing and playing your instrument by switching the mouthpiece.The Resistance Dial
The dial for the trumpet BERP should be positioned below the holes and pushed up to cover however much of the holes creates the desired resistance. Beginners usually have a better chance of getting a good buzz with slightly more resistance. Once a good buzz is achieved, resistance on the BERP should then be dialed similar to that on the instrument.