Product details:

These heavy duty floor grilles are made of 100% steel construction, making them the return air grille of choice for your high traffic areas. Find 65 sizes from 4 x 8 to 24 x 36. Discover how extremely rigid these heavy duty floor grilles are while still providing a smooth, firm surface. The free air space for the floor grille is over 75%. Scroll to bottom of page to see detailed drawings showing construction. Use for a hole opening size of 14 X 30. Overall faceplate dimensions of 15 13/16 x 31 13/16.