KUPO K-LOK 400A NEMA 3R Dust Cover are designed as weatherproof snap back protective cover to compatible with major brands of original single pole cam-type receptacles. Standard frame dimension allows retrofit existing application easily. The gasket offers a NEMA 3R rated environmental seal that provides a protection against falling rain, dust or frost, and also provides a safe way to cover exposed metal, while keeping the weather out when the receptacle is not used. Kupo Dust Cover is made from a high impact resistant, flame retardant ABS material and corrosion resistant stainless steel hardware. Color coding for easy phase identification.