DWV PVC Pipe To 4-Inch Hose Dust Collection Adapter Fitting Connect most 4 dust collection hoses to common 4 DWV PVC pipe Left-hand threaded 4 end fits inside most 4 dust collection hoses Smooth smaller diameter end slides inside most 4 DWV PVC pipe Smooth side outside diameter approximately 4.000 inches ABS material for rigidity and durability