NEMA 4 is a classification defined by the National Electrical Manufacturers Association that indicates a type of electrical enclosure. These enclosures are designed to protect electrical equipment from water, dust, and other environmental hazards. They are suitable for both indoor and outdoor use, making them versatile for various applications. The key features of a NEMA 4 enclosure include resistance to water splashes, rain, and hose-directed water, as well as protection against dust and falling debris. This makes them ideal for use in industries such as food processing, chemical manufacturing, and wastewater treatment, where equipment is exposed to harsh conditions.