Scosche OnStar Interface Chime Module: * Plug and play interface that allows replacement of a GM Class 2 factory stereo while retaining the OnStar system * On-board switching and amplification allows audio from the OnStar system to play through the two front factory speakers when OnStar is active * Will not disable the vehicle data bus, even if interface loses power * OnStar active LED and ignition on LED for visual indication * Smart sense mute output to either mute the aftermarket radio or to turn it off when OnStar is active * Provides a 12V accessory output * To retain the chimes in the vehicle, use Scosche DCGMCM2B12B