The Carlon® SuperBlue™ hard shell boxes combine the features of the hard shell thermoset box and the thermoplastic PVC style box to create a new rigid non-metallic wiring box. Molded out of specially formulated thermoplastic material, Carlon SuperBlue boxes are so strong they won't crack or break, even in extreme environments. So rigid, they resist flexing and hold their shape even under the worst conditions. They provide the largest wirefill capacity in their class and come with molded-in nailing flanges as well as molded-in clamps to make installation faster. Carlon SuperBlue boxes are lightweight, noncorrosive and nonconductive. They are designed to nest inside one another so they take up less shelf space and are easier to transport to job sites.