I don't know what it is...it has these nice big mirrors but for some reason, I don't feel they really show as much as they should. I am coming from an older Chevy and I could see the side of the truck all the way down to the ground and enough out but these seem more limited. Is it because the truck is so high that you won't be able to see the as much up close? I think that may be the problem. When just driving down the road, I have them set pretty well where I can see the back side of the truck, the road behind me, and enough in the lane to the side. The drivers side seems to be better, probably because I am closer to it so can move my head a bit. I guess what is bad is that I can't see the road immediately behind the truck or by the tire, like when you are backing into a parking space or something, it is hard to see the lines of the space, unless you tilt the mirrors way down. Does anyone else know what I am talking about or I am imagining things or just not used to the mirrors yet?