It is/was the replacement for the Tech 2. The Tech 2 only works on vehicles up to 2012-2013ish.
The Tech 2 wont work on the GM Global-A electrical architecture. So that means 2010+ camaro, caddy SRX, 2014+ impala, 2010+ equinox, 2014/2015+ full size trucks/SUV's, etc.
So if you want to...