Compatible with HW-304b/404b/704b/3000/CF500 Polar Aurora 525GPH box filters, this filter pad set is essential for maintaining a clean and healthy aquatic environment. Key Benefits: - Improves Water Quality: Effectively removes discoloration, odors, and dissolved fish waste, ensuring crystal-clear water for your aquatic life. - Comprehensive Filtration: Includes 4 Sponge Biofilter Pads (1 Crude, 2 Medium, 1 Fine) that capture visible debris without impeding water flow. Simply rinse and reuse to maintain performance. Product Features: - Easy Installation: Designed for hassle-free setup, these filter pads fit seamlessly into your cartridge filter without the need for complex tools, saving you time and enhancing productivity. - Cost-Effective Solution: As a non-original replacement option, these pads meet OEM standards and extend the lifespan of your existing filter media. Usage Scenarios: 1. Aquarium Maintenance: Ideal for regular upkeep of home aquariums, these pads help maintain optimal water conditions for fish and plants. 2. Fish Breeding Tanks: Essential for breeding environments where clean water is critical for the health of fry and adult fish. 3. Aquatic Displays: Perfect for use in aquariums showcased in homes or businesses, ensuring water clarity and odor control. Note: Due to vacuum packaging, the pads may appear thinner upon opening. This does not affect their filtration capability. To restore their original size, soak the sponge pads in water for 5-10 minutes before use.