Rear-approaching headlight glare can wreak havoc on your night driving vision. Youll be left alone in the dark with the fast moving hazards of the road. Ensure this doesnt happen with the Gentex K2 Auto-Dimming Rear View Mirror. The K2 Auto-Dimming Rear View Mirror uses high-tech sensors to detect offending light. Instantly the mirror eliminates dangerous glare with its intelligent circuitry leaving your vision intact. Whats more less glare means less eyestrain and driver fatigue. The K2 windshield-mounted mirror comes complete with detailed installation instructions and all necessary hardware - perfect for the experienced do-it-yourselfer or professional installer with some wiring required.Features. Gentex Auto-Dimming Rear View Mirrors eliminate the glare of headlights behind you for safer nighttime driving. Mirror automatically dims as it detects glare - the brighter the glare the more the mirror dims. Dimension - 12 x 6.5 x 4.75 in.