Describes those general-purpose metal outlet boxes, device boxes, covers, and supports that are widely used by the consumer. These items are designed to facilitate the pulling of wires, to protect and facilitate wiring splices and taps, to provide a means of mounting and protecting wiring devices, and to provide a connection for rigid conduit, electrical metallic tubing, armored cable, metal clad cable, nonmetallic sheathed cable, flexible metallic conduit and knob-and-tube wiring systems.

NEMA OS 1:2003