UNILETS® Cast device box made of malleable iron for high tensile strength and ductility. It provides greater resistance to impact and shock. Both malleable iron and aluminium boxes have ridge top construction for positive cover/gasket/box fit. Corrosion-resistant, ideal for indoor and outdoor installations. Weatherproof, raintight and dust-tight when used with cast gasketed covers. Accurately tapped, tapered threads for tight, rigid joints, ground continuity. Covers have captive stainless steel screws to speed installation, prevent freezing of screws. Malleable iron boxes and covers are triple-coated with zinc electroplate, chromate and aluminium polymer enamel.