Hubbell-Raco 5236 1-Gang Rectangular Floor Box with Brass Plate and Receptacle Box is made of cast iron construction Box has gray powder coat paint inside and out for additional corrosion resistance Two 3/4 in. threaded side openings at base of box and one 1/2 in. and one 3/4 in. threaded opening on bottom of box Non-adjustable, mop tight