Hey, upgrading the speakers in your GM truck or SUV? This Red Wolf kit makes it SO much easier. It's a 6.5-inch speaker adapter spacer ring AND a wiring harness, all in one. The spacer is made of tough ABS plastic and fits perfectly into your factory door holes, so your new aftermarket speakers mount up right. The wiring harness is the real time-saver – it has connectors that plug straight into your car's factory wiring on one end and standard fast-on connectors for your new speakers on the other. No cutting, no splicing, no messing with electrical tape. It's true plug-and-play. This kit fits a HUGE list of GM vehicles from about 1988 to 2012, including the Chevy Silverado, Tahoe, Suburban; GMC Sierra, Yukon; Buick Regal, LeSabre; Cadillac Escalade, DeVille; and many more (check the full list in the description to be sure!). Saves you a ton of time and hassle on your install, and the copper wiring ensures great sound quality. A must-have for any DIY car audio project on these models.