For installing flush floor boxes, look no further than Arlington's Floor Box Kits. Can be installed in an existing wood or concrete floor. Measuring 3.5" round, our UL listed non-metallic floor box offers a convenient way to install a duplex receptacle flush with the floor. This kit comes with non-metallic box, round metal cover, non-metallic gasket support plate, gasket, UL listed 15A tamper resistant duplex receptacle, NM94 and NM95 cable connectors, (3) #8 x 1/2" flat head screws, and (1) #6 x 1/2" screw. Box has a volume of 15.0 cubic inches. Metal cover is brass with threaded plugs.