I do most of my maintenance myself, and something as simple as changing tires is one of the most important maintenance items. However, in our brave new world where everything in a car is computerized, you need a device that will trick the car's computer into accurately recognizing the position of your tires so that systems, including pressure monitoring and even traction control, are able to accurately relay information . Official GM equipment is quite expensive, and going to a dealer or other store for this simple service item is stupid to me. That's why I bought this item. My rig has factory 20" wheels and tires and TPM sensors. This item worked great and fast. In less than 15 seconds per wheel, the system was reprogrammed to recognize new tire positions after a spin. I tested this by setting a different PSI on each bus and noting the IC data before and after using the tool. It was perfect. Not having this device at this price point is insane.