DWV PVC Pipe To 4-Inch Port Dust Collection Adapter Fitting Connect most 4 dust collection fittings to most common 4 DWV PVC pipe Tapered 4 ID end fits over 4 port found on many dust collection fittings Small diameter end slides inside most 4 DWV PVC pipe Smaller side outside diameter approximately 4.000 inches ABS material for rigidity and durability