This is the iDatalink Maestro ADS-MRR, the world's most advanced aftermarket head-unit interface module. Compatible with a number of vehicle specific t-harnesses, this module can make installing an aftermarket head unit in many new vehicles much much easier.
It will retain your steering wheel controls, retain and interface with OEM amplified audio systems, provide on screen vehicle gauges and vehicle information (not applicable to all vehicles) and more.
As taken from iDatalink's Website:
Web-programmable radio replacement interface for integration with factory systems including steering wheel controls, media player, hands-free telephone, voice commands, and satellite radio modules. Also displays vehicle information (performance gauges, climate controls, battery voltage, check engine codes and more) with iDatalink-compatible radios. Basic radio replacement features also available with non-iDatalink-compatible radios.