NorWesCo 596137 7.25" x 18.5" ABS Plastic Foundation Vent, Gray NorWesCo 596137 7.25" x 18.5" ABS Plastic Foundation Vent, Gray Features: Adjustable design fits 6" or 8" foundations Designed to accept optional dampers Nail holes break away when forms are removed Tough ABS construction with 1/4" galvanized steel Gray Size: 7-1/4" x 18-1/2" 100 SQIN Free Area For 6 Â and 8 Â poured foundations Plastic *Image may vary by size, material or color