Manufacturer and Model Information:Model # KWY126 The KWY126 Reducer replaces Jet JW1044 is ideal for professional and enthusiast woodworkers who work with shop vacuums or the equivalent. The 4 inch to 2-1/2 inch Reducer allows you to step down from a larger size hose or machine. The reducer connects 4 inch line to 2.5 inch dust ports. The step down increases air velocity where it is needed the most. With an outer diameter of 2.5 inch x 4 inch, this reducer lets you adapt to a smaller hose or machine. It connects to a standard 4 inch and 2.5 inch hose using hose clamps. Replaces Big Horn 11427 4 inch x 2-1/2 inch reducer allows you to step down from a larger size hose or machine Connects 4 inch line to 2.5 inch dust ports Length: 3-1/2 inch Replaces JW1044, Big Horn 11427 Outer diameter: 4 inch x 2-1/2 inch