This is an Antenna Adapter commonly found on European vehicles and sometimes on Domestic. This set up is for two adapters, one normal and one reverse. It allows you to plug into the factory antenna to adapt to the standard (motorola style) for your device like a FM modulator, and then back to the factory style antenna plug to go back into the factory stereo.

Please visit www.MetraOnline.com to use their fit guide to determine if this is the correct antenna adapter for your vehicle. Thank you.