Replacement Vent Inserts, No Frame: Envisivent Flush Mount Removable Air Supply, 12” x 6” (Duct Opening)/Requires 13" x 7" Drywall OpeningKey Description A replacement vent cover insert for CB5054. *To ensure you select the correct Envisivent product size, be sure to review our Sizing Guide in our Resource section. Key Features Mud in flush mounted Ideal for wall or ceiling 16 rectangular straight vertical slots Over 20 square inches of open vent area 4 magnetic tabs on the vent cover for easy removal Moisture, mold, and water resistant Primed and ready to paint Eco friendly