This unique product will convert your High Level speaker level signal from a factory installed amplifier or head unit to a high quality, low noise RCA pre-amp signal with summing options and Bluetooth for music input streaming. 

Main features: 
a. Selectable audio and bluetooth signal input
b. Signal auto sensing turn on/off function.
c. Adjustable Summed Output.
d. Level Matching Controls

Supply voltage:    8.5V-16V DC
Input Level:    30mV ~ 35V RMS
Remote out :    Yes
Channels:      12 channel input / bluetooth input 
Maximum output voltage  1KHz 1% THD ( each channel):     4.8 +/-0.4V  RMS
Maximum input voltage  1KHz ( each channel):    35 +/-1V  RMS
Frequency Response:    10Hz - 60KHz
S/N Ratio  ( A- weighted referred to 3V output ):      >105dB
THD+N  (20Hz-20kHz, referred to 3V output):    <0.1%
Channel separation (1KHz, referred to 3V output ):    <-70dB
Gain Range (1KHz, referred to 3V output return to zero ):     -14 ~0 dB
Signal Summing options:    Yes
DIMENSION(mm):    227x148x31