FUNCTION: Maximizes the efficiency of your dust collection system by directing and regulating the air from one machine to another FEATURES: This self cleaning blast gate greatly reduces clogs or chip build-up, possesses an easy-sliding gate that slides through the housing and contains a built-in stop locking stop to perfect gate alignment QUALITY: Made with premium ABS plastic, this unit was designed for durability and is abrasion - to withstand daily wear & tear from dirt, sawdust and woodchips SPECIFICATIONS: Accepts 4inch ID dust hose, port or vacuum fitting / Nominal end measures 3-61/64inch O.D. and 3-3/4inch I.D.