I have an aftermarket one that's made by Gentek, it looks just like most of the factory ones that I've seen. Every so often it loses it's calibration (says "cal" IIRC...haven't driven the truck since November). Any ideas on why that happens? (sorry for the thread hijack Joshua). Oh yea, the mirror has compass, temp, and is auto-dimming...I love the auto dimming feature, especially when I'm driving with the sliding rear window open and some tool comes up behind me with the highs on.

 

Hijack away. all i had to do is push the damn button to turn it on. lol