3-Gang Fire Classified Steel Floor Box. Adjustment range over deck of 2" (51mm) minimum to 6-1/2" (165mm) maximum. One 1 1/4" (32mm)and two 2" (51mm) conduit feed openings. Inside Gange Capacity - 67.5 cubic inches. Outside Gang Capacity - 54 cubic inches each gang. This floor box preserves up to a 3- hour fire rating of floors in which it has been installed.