The HR155 from Rolls is a rackmount monitor speaker that provides powerful audio in a compact design. The unit has an all-metal chassis for lasting durability. The rear panel features an XLR line input and stereo RCA line inputs and outputs. The front panel has a stereo 3.5mm line input. This variety of connectors allows you to connect virtually any line-level sound source including mixers, CD players, iPods, and more.