This is one smart mirror.  It automatically detects glare and dims making afterdark road runs easier on your eyes.  The brighter the lights behind you, the darker the mirror becomes.  That preserves your vision and lets you keep your hands on the wheel instead of fiddling with the mirror.  Along with a digital compass it features a temperature gauge. For Nissan Frontier 2004-2008 and Nissan Altima 2002-2006