1. The robotic pool cleaning bags are made of nylon with strong stitching and tight weaving. The fabric and weaving materials are the same as those of models 280/480. 2. They can accommodate various debris such as leaves, bugs, branches, sand, silt, etc., and are not easily damaged. 3. The extra-wide zipper opening makes it easy to empty and clean the filtered debris inside the bag. With Velcro, it is convenient to disassemble and install, and it can be removed for cleaning in just a few seconds. 4. This universal filter bag is equipped with particularly strong Velcro and is designed to firmly snap onto the elbow pipe and close tightly at the top. The safe and reliable closure method ensures its reliability. 5. It can fit the 280 and 480 universal saddle bags (parts K13 and K16). You will receive two packs of durable vacuum cleaning bags. In daily use, your filter bag may be damaged or worn out and unable to be used further. 6. Method for replacing the pool cleaning bag: Step 1: Turn off the booster pump, disconnect the hose from the dedicated pressure cleaner line, and then remove the cleaner from the pool. Step 2: Locate the universal zipper bag on the top of the cleaner. The plastic sleeve of the bag is the fastener that holds the bag in place on the cleaner during operation. Step 3: To remove the pool cleaning bag, rotate the plastic sleeve of the bag slightly clockwise or counter - clockwise to release the pressure tabs inside the cleaner body. Step 4: Discard the used or damaged zippered filter bag. Step 5: Pick up the new pool filter bag, align the pressure tabs on the bag sleeve with the arrow on the cleaner connection hose, and then slide it down until you hear a "click". 7. Package contents: 2 Polaris universal bags. 8. Precautions: 1. These replacement vacuum bags fit tightly. You may twist slightly when pressing the buttons. 2. It is advisable to fully tuck the zipper puller inside before fully zipping up. 3. When putting it into the water for the first time, you need to squeeze out all the air in the spare bag.