The Accessory Pack for the Zing Bagged Canister Vacuums includes 5 dust bags, 1 post motor filter, and 1 pre motor filter. It is best to check the dirt level in the bag before each use. For best performance, it is rmended that you change your bag when it is 1/2 to 2/3 full or when the outside of the bag feels firm to the touch. When accumulated, small dust particles can keep the air from circulating; this can reduce the suction in your vacuum. You may need to change your bag more frequently when vacuuming fine dust and debris, pet hair or new carpet. It is also rmended to check your vacuum’s filters at the same time you check the bag.