This is the Axxess AXSWC | ASWC-1 Steering Wheel Control Interface module. This is a programmable module which will allow you to retain the use of your OEM equipped steering wheel audio controls (vehicle mist be equipped with steering wheel audio controls).
As taken from the Axxess Website:
The AXSWC is a universal steering wheel control interface that can be used on most any vehicle with steering wheel controls. Designed to be used with today's top aftermarket radio manufactures like Pioneer, Sony, Alpine, Kenwood, Eclipse, JVC, and others, the AXSWC is all you'll need to retain the OEM steering wheel controls. The AXSWC has the ability to auto-detect many vehicle makes and aftermarket radios and it will preset the steering wheel controls to the aftermarket radio automatically so no programming is required. If desired the ASWC can be manually programmed so the user can make the steering wheel controls function they way they want them to, only limited by the functions of the aftermarket radio.