POWERTEC 70133 2-1/2-Inch Blast Gate for Vacuum/Dust Collector Maximizes the efficiency of dust collection system by directing the air flow from one machine to another 2-1/2-Inch outlet diameter Easy sliding gate action saves you effort and time Tough, durable ABS material 2-1/2-Inch nominal end measure 2-31/64-Inch O.D. and 2-19/64-Inch I.D.