
| Call Size | A | B | C | D | Maximum Roof Opening |
| 16 x 16 | 15 | 15 | 21-1/2 | 21-1/2 | 14-1/2 x 14-1/2 |
| 16 x 24 | 15 | 23 | 21-1/2 | 29-1/2 | 14-1/2 x 22-1/2 |
| 16 x 32 | 15 | 31 | 21-1/2 | 37-1/2 | 14-1/2 x 30-1/2 |
| 16 x 48 | 15 | 47 | 21-1/2 | 53-1/2 | 14-1/2 x 46-1/2 |
| 24 x 24 | 23 | 23 | 29-1/2 | 29-1/2 | 22-1/2 x 22-1/2 |
| 24 x 32 | 23 | 31 | 29-1/2 | 37-1/2 | 22-1/2 x 30-1/2 |
| 24 x 48 | 23 | 47 | 29-1/2 | 53-1/2 | 22-1/2 x 46-1/2 |
| 32 x 32 | 31 | 31 | 37-1/2 | 37-1/2 | 30-1/2 x 30-1/2 |
| 48 x 48 | 47 | 47 | 53-1/2 | 53-1/2 | 46-1/2 x 46-1/2 |
