Kaufhof KWY136 4 Inch Left Hand Threaded / Quick Connect Splicer For Wood Shop Dust Collection Diameter: 4 inch | Length: 4-1/4 inch Left hand Threaded splicer Connects to a 4 inch dust collection hose, Use the KWY112 for Right hand Easy to remove the tapered end from a "T", "Y", elbow or blast gate replaces Big Horn 11415, Jet JW1047