The Kirby vacuum system uses a disposable filter bag. When the "Full" marker on the side of the fabric bag encasing the disposable bag is visible, it's time to change the bag in your Kirby vacuum. Kirby recommends only using original Kirby replacement parts. You can order a Kirby filter bag from your Kirby service center or from Kirby.com. The current Kirby vacuum cleaner model is the Sentria.
Turn the Kirby system off and unplug it. Locate the zipper on the bottom edge of the fabric bag. Unzip it to expose the disposable filter bag.
Pull the top edge of the bag out partially. You'll see where the cardboard panel connects to the suction tube.
Grasp the cardboard panel. Rotate it counterclockwise to unlock the filter bag. Pull the filter bag out of the fabric bag. Dispose of the the old bag.
Insert the new filter bag into the fabric bag. Connect the cardboard panel to the suction tube. Make sure the top tabs on the cardboard panel are aligned with the the tabs on the suction tube.
Turn the cardboard panel clockwise to lock it into place. Verify the filter bag is fully stored within the fabric bag. Zip the fabric bag to secure it.