The 131 provides not only offers standard features like single-channel, 31, 1/3 octave bands, ISO frequency centers, +/- 12 dB input gain range, and switchable 50Hz/12 dB per octave low-cut filter, but also includes other insightful features. These features include 20 mm faders; selectable +/-6dB or +/-12dB boost/cut range for precise gain adjustments; XLR, and 1/4'' TRS connectors for installation ease; balanced inputs and outputs for quiet operation.