Superblue boxes combine the features of the hard shell thermoset box and the thermoplastic PVC style box to create a 'new' rigid non-metallic wiring boxMolded out of specially formulated thermoplastic materialSuperblue boxes will not crack or break in extreme environmentsResist flexing and hold their shape even in the worst applicationsDesigned to nest inside each other to take up less space on the shelf or in the truck, while still providing the largest wirefill capacity in their classAll PVC boxes are permissible for use with 90 deg c connectors