Review on POWERTEC 70147 Tapered Adapter, 4-Inch to 2.25-Inch by Eric Mueller

The problem with this and almost all dust collection adapters is that the dimensions are not fully specified. So if you have a "4" fitting on your tool (like my Jet 14 bandsaw), the outside diameters of the fitting and adapter are the same, i.e. one will not fit the other. at the end of the vacuum hose. In my case I was ready to throw this thing away (not worth sending back) but I ended up attaching it to a bandsaw with a gorilla and made an adapter for the vacuum end using 4 folded/glued pieces of wood with holes 2-1/ 4 inches. It looks a little clunky but only works because I already had the right size hole saw.