The SubZero 4 Channel Headphone Amp is a robust and high-quality headphone amplifier with four headphone outputs, perfect for use when professional monitoring is required. Each of the 4 channels feature independent level controls for each headphone output, allowing you dial in the desired amount of volume, making it ideal for studio, live and a variety of other applications. The metal construction makes the SubZero 4 Channel Headphone Amp a reliable addition to any studio.