SPECIFICATIONS FOUNDATION VENT #FA109000 Aluminum· N.F.V.: 36 sq. in. • 1/8 in. Screen • Rough Opening: 8 in. x 16 in. 1.3 in. 16.9 in. 42.9 cm 0.6 in. 1.5 cm 7.9 in. 20 cm 0.9 in. 2.3 cm 3.