The HMB115 converts consumer level stereo RCA signals to balanced XLR professional line level, and back. One side of the unit, labeled 1, has two XLR inputs and stereo RCA outputs. The other side labeled 2, has stereo RCA inputs and two XLR outputs. Each side has stereo level controls. An additional benefit of the MHMB115 is that it will act as a balanced XLR line level control.