With 1 in W frame for new construction or to replace old foundation vents. Fits standard 8 in x 16 in concrete block opening. Operates automatically without electricity, opens at 70 deg F, closes at 40 (approximately). Simple homeowner/DIYer snap-in installation, with color matched set screws for additional stability. Removable back for maintenance and cleaning. Screened with 1/8 in heavy-duty aluminum mesh. High-density thermo-plastic construction. All metal parts are corrosion-resistant stainless steel. Aluminum louvers. No mortar required for installation. 62 sq-in net-free area. 8 in x 16 in.