Fits 2012 Chevy 2500HD regardless of what the website says. This is for the Stabilitrac system and my truck was fitted with this system. Simply put, you should have two incoming and four outgoing brake lines. Now you've made sure you have the right part. Complicated installation. It comes off fairly easily, but be prepared for brake fluid to drain out of all of your lines as you remove each one. This assembly comes out of the transfer case, fits snugly but comes out. Reassemble in reverse order, but be careful not to push the wires into the threaded sockets. You can't see what you're doing and need to feel the lines activate. Almost screwed up in one line. Once inside you need to prime and bleed the master cylinder and then bleed the brake lines and then bleed the anti-lock brakes using the software tool. Buy a liter can of brake fluid. You will need it. Once you've deflated the lines, check for leaks and clear your codes. The item was well packaged and works. This is just the hardware side, no electronics. My old one had a leaking internal valve on the internal electronics around a magnet.