note: all opera grilles have a ridge on the back unless they are for 2.25 inch width duct openings in which case they are flat.
| duct opening size | grille only | grille with damper |
| 2.25
by 10 inches (3 inches wide overall) |
$23.95 | n/a |
| 2.25
by 14 inches (3 inches wide overall) |
$26.95 | n/a |
| 4 by 8 inches | $36.95 | $44.95 |
| 4 by 10 inches | $36.95 | $47.95 |
| 4 by 12 inches | $37.95 | $51.95 |
| 4 by 14 inches | $36.95 | $55.95 |
| 6 by 6 inches | $34.95 | $47.95 |
| 6 by 10 inches | $46.95 | $60.95 |
| 6 by 12 inches | $46.95 | $63.95 |
| 6 by 14 inches | $54.95 | $71.95 |
| 6 by 30 inches | $165.95 | n/a |
| 8 by 12 inches | $65.95 | $69.95 |
| 8 by 14 inches | $68.95 | $76.95 |
| 8 by 8 inches | $42.95 | $52.95 |
| 10 by 10 inches | $66.95 | $60.95 |
| 10 by 14 inches | $89.95 | $85.95 |
| 12 by 12 inches | $79.95 | $89.95 |
| 14 by 14 inches | $98.95 | $98.95 |
| 14 by 24 inches | $175.95 | n/a |
| 14 by 30 inches | $185.95 | n/a |
| 16 by 16 inches | $165.95 | n/a |
| 20 by 20 inches | $185.95 | n/a |
| 20 by 25 inches | $285.95 | n/a |
| 20 by 30 inches | $385.95 | n/a |
| 24 by 24 inches | $385.95 | n/a |