Reducer straight connector：KQ2H
| Tube ΦD | Model | Joint External diameter φ | Joint Length L | Reducing air pipe External Diameter |
| φ4 | KQ2H04-06 | 13.2 | 34.5 | φ6 |
| KQ2H04-08 | 15.6 | 38.5 | φ8 | |
| φ6 | KQ2H06-08 | 15.6 | 38.5 | φ8 |
| KQ2H06-10 | 18.8 | 42.5 | φ10 | |
| φ8 | KQ2H08-10 | 18.8 | 42.5 | φ10 |
| KQ2H08-12 | 21.3 | 44.5 | φ12 | |
| φ10 | KQ2H10-12 | 21.3 | 44.5 | φ12 |
| φ12 | KQ2H12-16 | 26.5 | 56.5 | φ16 |
