Custom-Designed Compatibility: Engineered to be a precise fit for Marineland Magnum 350 (ML350) canisters and Pro Series filters. Replaces the Rite-Size R foam sleeves effortlessly, ensuring a snug fit with no gaps for unfiltered water to bypass, keeping your filtration system running at peak performance Superior Dual Filtration: High-density bio-foam provides excellent mechanical and biological filtration. The porous structure effectively traps fine debris, fish waste, and uneaten food, while providing a vast surface area for beneficial nitrifying bacteria to colonize, ensuring a crystal-clear and healthy aquatic environment Durable and Reusable Construction: Made from high-quality open-cell poly-fiber. Unlike flimsy alternatives, our filter sponges are resilient and washable. Simply rinse with aquarium water during maintenance and reuse multiple times without losing shape Safe for All Aquatic Life: This filter media is 100% non-toxic, BPA-free, and safe for both freshwater and saltwater setups. It won't leach chemicals into the water or affect the pH balance, suitable for sensitive fish, shrimp, and coral reefs Optimized Dimensions and Value Pack: Each pad measures exactly 6.28 x 5.5 x 0.78 inches, optimized for maximum water flow and debris retention. 6-Pack provides a long-lasting supply, ensuring you always have a clean replacement ready to keep your aquarium pristine and your fish thriving Easy Maintenance and Installation: Quick and simple to install in your Marineland Magnum 350 filter system, these foam pads require minimal effort to replace during routine maintenance, helping you maintain optimal water quality with ease Aquarium Bio Fitler Media Sponge, 6.28 x 5.5 x 0.78 inch 6pcs Foam Filter Pad Inserts for ML350