Attributes . For surface mounting of alarm devices and safety signals designed to fit into 4'' (102mm) square back boxes. Available in red and ivory finishes. Cover is 2 3/4'' (70mm) deep and has three twistouts for raceways on each side. Base has 1/2'' and 1'' concentric and single-gang box KOs. Accepts NEMA double-gang standard faceplates. . Names