Brand is Gold Line. I got the mac-daddy $500 model. I'm pretty sure it is pro-rated from purchase date. From the research I did, the roof and its seal are worth protecting. If I get 3 years out of it, I will consider it money well spent.
The added benefit (after putting covers on the roof vents) was that I can leave the vents open and the windows cracked to keep it from getting too hot inside.