Vintage White Steel Baseboard Registers - 15" X 12" Outside Dimensions White Powder Coated Steel Gravity Baseboard Vents Gravity vent that fits 15" x 12" overall or a hole at least 12" x 8" This gravity vent has a flap damper to allow maximum air flow Top projection is 1" out from wall and 2.5" out from wall Replace the hard to find and beat up old vent...Finally