The DOD SR231QXLR Graphic EQ is two constant Q, 31-band, 1/3-octave equalizers in a steel chassis that inhabits only two rackspaces. Low-cut filter at 50Hz with a 12dB/octave slope. Back panel boasts two balanced XLR and two 1/4" inputs and the same outputs. Fully shielded internal power supply, steel chassis, and high-end circuitry for crystal-clear signal path.