A reducer coupling is used to join together two different sizes of PVC sewer pipe.

| Size | IPEX # | UPC | L | W | H | WT | |
|---|---|---|---|---|---|---|---|
| 4" x 3" | 040654 | 622454406544 | incm | 4.5 11.4 | 4.5 11.4 | 4.0 10.2 | 0.33 lbs0.15 kg | 
| 6" x 4" | 040661 | 622454406612 | incm | 6.7 17.0 | 6.7 17.0 | 6.1 15.4 | 1.08 lbs0.49 kg |