Product info:
2-channel line driver/output converter with bass restoration
works with factory and aftermarket systems
selectable ground isolation modes: GND, ISO, 200-ohm
preamp and speaker-level inputs
selectable input signal grounding: balanced, unbalanced
variable input gain control with Max indicator light
speaker-level inputs handle up to 40V (400 watts RMS)
selectable speaker input impedance loads: 20, 60, or 20k ohms
Epicenter bass restoration
recreates missing low-frequency signal content
Para-Bass controls adjust center-frequency and width of bass processing
selectable Programmable Frequency Match (PFM) 12 dB/octave subsonic filter: off, 15 Hz, 24 Hz
variable output gain control with Max indicator light
outputs up to 9.5 Vrms
selectable maximum output peak voltage limiter: 5V, 7.5V, 10V
More info:

ACR-4 wired remote included
selectable turn-on trigger modes: 12V remote, DC offset (GTO), audio signal detect
remote 12V trigger output
wiring, fuse, and hardware not included with device
18-gauge power and ground leads and a 1-amp fuse recommended
dimensions: 8" W x 1" H x 3" D