Gentex Corporation designs, develops, manufactures, and markets automatic-dimming rearview mirrors and electronics for the automotive industry; dimmable aircraft windows for the aviation industry; and commercial smoke alarms and signaling devices for the fire protection industry worldwide. It offers automotive products, including interior and exterior electrochromic automatic-dimming rearview mirrors, automotive electronics, and interior and exterior non-automatic-dimming rearview mirrors with electronic features for automotive passenger cars, light trucks, pick-up trucks, sport utility vehicles, and vans for original equipment manufacturers, tier one automotive mirror manufacturers, and various aftermarket and accessory customers. The company also provides photoelectric smoke detectors and alarms, audible and visual signaling alarms, photoelectric smoke detectors and electrochemical carbon monoxide alarms, electrochemical carbon monoxide detectors and alarms, and bells and speakers for use in fire detection systems in office buildings, hotels, and other commercial and residential establishments. Gentex Corporation sells its fire protection products directly, as well as through sales managers and manufacturer representative organizations to fire protection and security product distributors, electrical wholesale houses, and original equipment manufacturers of fire protection systems. The company was founded in 1974 and is headquartered in Zeeland, Michigan.