The auto dimming of our mirror works automatically when you start the engine, then the indicator will light up. The light sensor on the back of the rearview mirror will always detect the ambient light. The auto-dimming mirror doest work in a broad day for the adequate daylight. However, when night falls and the ambient light is weak, the auto-dimming start to work and automatically dims to eliminate the glare of rearward-approaching wechicles. Furthermore, the degree of brightness of the auto-dimming glass depends on the level of the light. The stronger the light from the back of the car is, the darker the glass will be. Hence it protects drivers from becoming dizzy and avoiding car accidents

• Car Auto Dimming Rear View Mirror, Germid auto-dimming rearview mirror utilizes 3rd generation electrochromic material and dual photoelectric sensors to automatically adjust the dimming level and eliminate glare, giving you a safer and more comfortable driving experience.
• Original Factory Style & Universal Fitness, With its sleek and modern design, our mirror complements your vehicles original factory style. Its replaceable rearview mirror bracket with double-jointed ball provides adjustable visibility and universal fit for most car models.
• High Quality Material-4.0 mm Thickness Glass, Germid mirror is made with factory OEM quality 4.0 mm glass, which meets vehicle safety standards and offers high reflectance for a clear and crisp image.
• Easy for Installation, Included with the mirror is a Door Clip Panel Trim Removal Tool, making it easy to hide the wire during installation. Moreover, our patent replaceable rearview mirror bracket allows for easy installation and replacement.