One end features a clamp-style coupling, and the other end is equipped with a double-grooved coupling, used for connecting grooved products with double-grooved products.
| NO. | Size | External Dia.(mm) |
| 1 | 5''×2 1/2'' | 133.0×76.1 |
| 2 | 5''×3'' | 133.0×88.9 |
| 3 | 5''×4'' | 133.0×108 |
| 4 | 6''×2 1/2'' | 159.0×76.1 |
| 5 | 6''×3'' | 159.0×88.9 |
| 6 | 6''×4'' | 159.0×108 |
| 7 | 8''×2 1/2'' | 219.0×76.1 |
| 8 | 8''×3'' | 219.0×88.9 |
| 9 | 8''×4'' | 219.0×108 |
| 10 | 10''×2 1/2'' | 273.0×76.1 |
| 11 | 10''×3'' | 273.0×88.9 |
| 12 | 10''×4'' | 273.0×108 |
| 13 | 12''×4'' | 325.0×108 |
