part# was 13540313, but in searching for one I found several others at the time that also said they would fit. This was 3-4 months ago and it seems as if the mounting pad was slightly different but it still fit with no problems. Wish I would have done it sooner, not sure why Chevy didn't put it on there to begin with. Just be careful when prying the connector off of the roof, I guess they used some kind of hot glue and you have to be careful not to break it. If you do you probably would have a hard time finding another one and then have to go to the trouble of working in a very small space splicing wires. I used a pocket knife and several different picks and just kept working around it until it finally popped loose.