2002 – 2003 Chevy Trailblazer & GMC Envoy Radio AM FM CD Player with Aux Input Upgraded with iPod Aux In directly on the face! For use with iPod, iPad, iPhone, MP3 Player, Sirius XM Satellite, Android Phone & more! Part Number: 15195521 Compatible Part Numbers: 15169545 / 15058230 Option Code: UN0. This radio will need to be unlocked by a GM dealer and paired to your vehicle. This is for a Chevrolet Trailblazer and GMC Envoy factory OEM AM FM CD Player Radio that has been upgraded with an aux input for use with iPhone, iPod, MP3 Players, Satellite Radio, Android Phones and more! You will not lose any functionality when the auxiliary input is in use and the radio will have all factory OEM features! Please confirm that this is the radio your vehicle requires as some of the vehicles used more than one style of radio. The Aux Input is a snap to operate…literally! Just plug in your 3.5 mm cable and it will play in full, crisp, clean quality. When you want to listen to the radio again, simply unplug the cable! The audio is full quality and takes advantage of all sound controls on the radio. Forget those shoddy FM transmitters and listen to music the way it’s supposed to sound! Please Note: This radio will need to be unlocked upon installation in your vehicle. It can often be put into a fully functioning test mode for 10 minutes at a time without the vehicle running but will need to be taken to a dealer for permanent pairing. The price for this varies so please make arrangements before purchase.