The Shure A15BT Bridging Transformer can be used to connect balanced and unbalanced devices having different signal levels or impedances. Depending on the configuration, the A15BT provides a minor increase or decrease in signal level. The A15BT can be used to:Connect a mono output from an FM tuner or receiver to the input of a microphone mixerConnect a high-impedance microphone to a medium-impedance input on an audio recorderConnect a balanced line-level output from a mixer to an unbalanced Aux-level input on an amplifier or recorderConvert an unbalanced Aux-level output to a balanced 600 Ohm line output (example: Shure SCM268 Mixer)