Mazda CX-3 Auto Dimming Mirror with Compass and Homelink.The Genuine Mazda Accessory Auto-Dimming Rearview Mirror comes equipped with a bright LCD Compass to keep you on the right road and HomeLink® to make your life more convenient and safe. And it allows you to replace up to three of your transmitters with dedicated buttons on the mirror. The Auto-Dimming feature uses high-tech sensors to detect headlight glare and automatically dims to eliminate it, leaving your view of the road intact.