The AT8543 is an essential phantom power only in-line power module designed to complement the functionality of the ATM350a instrument microphone. This power module provides the necessary power for the microphone to operate effectively, ensuring optimal performance in various recording and live sound applications. With its low-frequency roll-off selection feature, the AT8543 helps to eliminate unwanted rumble and bass frequencies, resulting in clear and crisp audio reproduction. Its sleek black finish adds a professional touch to your setup.