3-Gang Fire Classified Steel Floor Box. Adjustment range over deck of 2'' (51mm) minimum to 5'' (127mm) maximum. Three 1 1/4'' (32mm) conduit feed openings. Inside Gang Capacity - 67.5 cubic inches. Outside Gang Capacity - 54 cubic inches each gang. This floor box preserves the 2-hour fire rating of floors in which it has been installed.