Product details:

Crawl Space Door System's FEMA Compliant Engineered Flood Vent has a 24" height x 24" width opening. It is surface mounted OVER the foundation opening and has a total dimension of 30" height x 30" width because of the frame for mounting . 1230 sq. ft of coverage. Engineered Cert included . Must have at least two flood vents on two different walls to be FEMA compliant. Nothing goes into the opening because it is surface mount. Engineered Cert included for your state. AL, CA, CO, DE, FL, GA, ID, LA, MD, MO, MS, NC, NJ, NY, NV, SC, TN, TX, VA FEMA Flood Louver - Patent No. Made of durable ABS plastic (no rust or rot) with a UV retardant. The flood vent is excellent for repairing, remolding and new construction.