Fire Classified 2-Compartment Box. For use in either concrete or wood floors. Fully adjustable with tunnel compartment. Supplied with one (1) duplex receptacle mounting plate, and one (1) communication mounting plate (RFB22AB). Other device plates sold separately. NOTE: For use in light weight concrete floors with a minimum pour depth of 3 1/4'' (83mm) over the crest of the deck. Floor Box spacing 2' on center and one for every 4 square feet in a span. Four (4) #12 AWG Type THHN Power Conductors or 48 #23 AWG (6 Cat. 6) Tele Data Conductors per gang. This box preserves the 2-hour fire rating of floors in which it is installed.