Hart & Cooley® Floor Register, Series: 531, 6 x 12 in, 11-7/8 in Duct Width, 5-7/8 in Duct Height, 13-3/8 in Overall Width, 70 to 250 cfm, Effective Area: 0.225 sq-ft Heating/0.25 sq-ft Cooling, 1/2 in Blade Spacing, Aluminum, Satin Anodized, Domestic