DustFX 4″ to 2.5″ “Y” fitting allows users to have a 2.5″ dust hose “Y” off their main 4″ dust line to attach to smaller dust inlets. An example would be a router table or tablesaw which use a main 4″ inlet for the majority of the dust suction but over top of the saw blade or router bit there might be a 2.5″ inlet to use as well to help pull dust right from the source.