The Audioarts HS-1 is a tiny ( 2-3/4" by 3-3/4") headphone station designed for broadcast use. It can be used as a free-standing unit or mounted underneath the counter with an optional bracket. Performance is clean, quiet and powerful, with wide dynamic range and ruler flat frequency response. The front panel has a 1/4" output phone jack, power LED and rotary level control. An internal HI/LO gain switch lets you match a wide range of input types.Rear connectors include dual RJ45 parallel inputs and 9VDC power in, that (like the TS-1) multiplies voltage and current to provide GREAT, LOUD sound to headphones of virtually any impedance. Input cable and special 9VDC negative center pin power supply included.