This is the Wavtech LINK4 Line Output Converter, 4-Channel.
When it comes to adding an amplifier or amplifiers to your factory audio system, the link4 does what models from competing brands just can't. Simply put, it is the most flexible 4-channel LOC available today.
The link4 can directly accept 4-channels of input and give you 4-channels of output. It can accept 2-channels of input and give you 4-channels of output. If you input 4-channels, you can sum them down to 2-channels of output. It even has a 3.5mm Auxiliary Input so you can add your phone or other portable device to the system.
No other 4-channel LOC can do all of that. As an added bonus, it includes our 'Patent Pending' Multi-Function Remote Level / Source Control that can adjust your subwoofers output level, the volume of the auxiliary source or serve as a Master Volume Control for your entire system. This is especially useful in OEM systems where speed sensitive volume or equalization are present.
Features:
4-Channel Line Output Converter
4-Channel Summing Processor
Multi-Function Remote Level / Source Control:
Master Volume Control
AUX Volume Control
Independent Ch3/4 Level
Source/Function Select
AUX 3.5mm Input
Differential Balanced Inputs
Low Output Impedance
Independent Variable Gains with Clip LEDs
2ch/4ch Input Select
2-Way Summing with Retained Ch3/4 Level Control
Auto Turn-On via DC-Offset or Audio Signal Detect
Generated +12V Remote Output
OEM Load Detect Compatible
Selectable Ground Isolation
Professional Grade Panel Mount RCA's
Locking Detachable Power and Speaker Input Terminals