Check the listing for details. FLUVAL PROVAC DUAL DENSITY FILTER PAD - 4 PACK - 11078. Condition: New. Listed at 11.99 USD. The Fluval ProVac Dual Density Filter Pad removes large and small waste particles for a thorough clean. It is suitable for the Fluval ProVac Gravel Cleaner (11077). It is an essential component of the ProVac system and serves to remove both large and small waste particles during the cleaning process. The dual density feature of the filter pad means that it can effectively capture and trap various sizes of debris, ensuring a thorough clean of your aquarium substrate. This helps to maintain the overall cleanliness and water quality of your aquarium. When using the Fluval ProVac Gravel Cleaner, you can place the Dual Density Filter Pad at the end of the intake tube. As water flows through the filter pad, it will filter out debris and prevent it from reentering the aquarium. Regularly replacing the filter pad is recommended to maintain optimal cleaning performance. The frequency of replacement will depend on the condition of your aquarium and the amount of waste it generates. Remember to refer to the product instructions and follow the manufacturer's guidelines for the Fluval ProVac Gravel Cleaner and the Dual Density Filter Pad to ensure proper usage and maintenance.