Black Circle
| Size | D1 | D | d | L | Part Number |
| 20 | 22.8 | 20.5 | 16.6 | 10.3 | AS28020 |
| 25 | 28.9 | 25.3 | 20.0 | 12.0 | AS28025 |
| 32 | 35 | 33.7 | 24.1 | 11.5 | AS28032 |
| 38 | 41.6 | 38.0 | 33.6 | 11.5 | AS28038 |
| Size | D1 | D | d | L | Part Number |
| 20 | 22.8 | 20.5 | 16.6 | 10.3 | AS28020 |
| 25 | 28.9 | 25.3 | 20.0 | 12.0 | AS28025 |
| 32 | 35 | 33.7 | 24.1 | 11.5 | AS28032 |
| 38 | 41.6 | 38.0 | 33.6 | 11.5 | AS28038 |
