A disposable open bag for a power tool such as a Shop-Vac cleaner has a mounting plate with an opening for receiving debris from the intake of the power tool. The mounting plate is also provided with a vent opening(s), e.g., to prevent the bag from closing in on the air filter and blocking the airflow. The said bag provides a cleaner and more convenient means of collection of the debris, leaves, and particulate matters directly into the bag.