Part number: 70295 is a 4 inch integrated blast gate clog resistant for dust collection systems. Function: Control air flow from one machine to another machine, so that dust treatment faster, better improve work efficiency. High quality material: The blast gates dust collection is made of industrial plastic, which is scratch-resistant and durable and lasts a long time. Adjustable: The airflow size can be controlled by sliding the plate, and the airflow can be effectively blocked when completely closed. If you have any problems please kindly contact us by logging in your Amazon Buyer Account, Find your order and click Contact Seller we will respond you in one business day.