This publication covers guidelines for selection and installation of general purpose and specialty metallic@ nonmetallic@ and composite outlet boxes such as device boxes@ fixture boxes@ and junction boxes; extension rings; covers; and flush device cover plates. The boxes addressed in these guidelines are intended for use in ordinary@ non-hazardous locations. With the exception of masonry boxes and some multigang boxes and floor boxes@ the boxes addressed in these guidelines are limited to 1650 cm? (100 in?) internal volume.?