Shure A15AS In-Line Switchable AttenuatorThe Shure A15AS Switchable In Line Attenuator reduces the level of any balanced microphone or line level signal by 15, 20, or 25 dB. It is specially suited to reducing the level of a high output microphone to prevent it from overloading the microphone input of a mixer or recorder in applications with high sound pressure levels. In addition, the A15AS may be used to reduce the level of a line level mixer output to prevent overloading the aux level