I just finished setting up a dust collection system with the 2hp motor from Harbor Freight. This separator fits on top of a $15 silver trash can from any big box home improvement store. The openings fit 4 in tubing perfectly and do a great job. I've filled a trash can twice now and I have no more than a gallon of dust in the bottom of my collection bags. Less chips and stuff that go through your impeller the better. I know building a thein baffle would be even better, but for the effort and low cost of this unit - it's all I'll ever need.