Allen & Heath's GR4 is a 4-zone mixer in a 1U chassis that can be rack-mounted or function as a desktop audio mixer. Built to offer 4 stereo inputs and 4 mic inputs with analog EQ on industry standard Phoenix connectors, plus 4 zone outputs; the GR4 can control 2 stereo zones and 2 additional mono zones (4 zones total)..PZA MORE SPECS