2-1/2" O.D. Hose to 4" O.D. Quick-Connect Dust Collection Fitting Tapered 4" ID Quick-Connect adaptor fits most machines with 4" OD dust-collection port Move fitting quickly from one machine to another by simply pushing adaptor over port 2-1/2" OD male thimble accepts most 2-1/2" dust-collection hoses 2-1/4" ID male thimble accepts most 2-1/4" hose end fittings and standard shopvac hose Rugged resin construction flexes rather than breaking