The Aluminum Blast Gates by POWERTEC. This blast gate gives you optimal control over directing air flow of your dust collection system by opening and closing select ducts. Most importantly, they help to conserve air volume and keeps suction strongest where dust is being produced, thus maximizing your workshop dust extraction. Universal Fit-The blast gates in 5 different OD are designed to accommodate any dust collector system with a 2-1/2 inch to 6-inch ID diameter hose, pipe, duct or fitting. They are extremely easy to install, use and offer maximum return on your investment in terms of effectiveness. If you're looking to increase the efficiency of your dust collection system, these woodworking accessories are a must. Premium Construction-These blast gates are designed with a highly durable cast aluminum body and premium steel sliding gate. Resistant to common abrasives, the impressive build withstands the harmful effects caused by wood chips, saw dust and other debris. When used alongside a capable dust collection system, these components provide exceptional quality for any professional workshop setting.