Gentex designs and manufactures electrochromic auto-dimming rearview mirrors for the automotive industry, holding roughly 79% worldwide market share in this product category. Gentex's mirrors use proprietary electrochromic technology to darken automatically in response to headlight glare, and the mirrors can be layered with add-on electronics including HomeLink (vehicle-to-home connectivity), Full Display Mirror (FDM, which streams live rear-view video to the interior mirror), driver monitoring systems (DMS), and cabin monitoring. Gentex sells directly to automotive OEMs and tier-1 suppliers globally under purchase orders or long-term supply agreements, with customers spanning GM, Ford, Toyota, Volkswagen, BMW, Tesla, Rivian, and Chinese domestic OEMs. The core business model is per-unit sales to OEMs, where revenue grows through three levers: light vehicle production volumes, nameplate penetration, and average selling price per mirror, which rises as more electronic features are added. In April 2025, Gentex acquired VOXX, adding premium audio brands (Klipsch, Onkyo, Integra), automotive aftermarket electronics, and consumer electronics sold through retail and e-commerce channels. Gentex's growth strategy centers on expanding content per vehicle through FDM adoption, DMS/CMS integration, and extending electrochromic technology to larger glass surfaces like visors and sunroofs. Gentex manufactures primarily in the U.S., which creates tariff exposure in China—a market that saw revenue decline sharply following U.S.-China tariff escalation.