Used approx. 6 months.  Was mounted under rear seat in 09 Avalanche, was never touched...mint condition.  This is necessary to add additional aftermarket speakers/subwoofers to factory system while maintaining all factory functions like steering wheel controls.  Add a JL sub box and amp to my factory BOSE system and it worked perfectly.  Traded the truck so I took this out first. 
 
 
 
  • AudioControl 2 channels of active speaker level inputs
  • Accepts 400 watt signals per channel
  • Features AccuBASS processing for correction of bass roll-off
  • Fixed and variable outputs with discrete level controls
  • GTO - Signal sensing inputs
  • Dual amplifier, 9.5 Volt pre-amp outs
  • Level matching controls
  • 12 Volt trigger output
  • Optional dash remote level control
  • Dimensions: 6-3/8"W x 3-1/8"D x 1-1/2"H