Speakercraft CTL02001 Line Level Audio A/B Switch Low Ohmic relay contacts provide lossless, distortion-free switching Octal switch provides precision delays from 0.5 seconds to 5 minutes to handle any music energy interval without false switching Sense level permits adjustment to accommodate a wide range of music level conditions for best switching threshold B status 3.5mm output jack provides 12V trigger to local devices where desired PS-1.0 power supply required