Mess-Free Media Hold - Durable nylon mesh filter media bags come pre-filled with activated carbon and provide a simple way to manage canister filtration. The fine mesh bag keeps fish tank media securely contained inside the tray while allowing steady water movement through compatible systems. Clearer Water Support - Designed to help trap loose particulate matter, these aquarium filter bags assist in reducing odors and discoloration. Suitable for freshwater and saltwater aquariums seeking dependable, everyday filtration performance. Designed for Cascade Trays - Specifically sized for Cascade Canister Filters, these mesh filter media bags sit neatly inside designated trays, helping keep media organized and reduce shifting during operation while maintaining consistent flow. Smart Size & Simple Care - Each nylon mesh filter bag measures 8” x 4” and holds 8 oz of media, sized for easy placement inside compatible trays. Rinse with cold water before use, avoid soap, and refresh media every 4-6 weeks to keep maintenance quick and consistent. Penn-Plax Legacy - With over 60 years of innovation, Penn-Plax creates expertly crafted, dependable pet products designed to enrich habitats, inspire creativity, and promote the health and happiness of pets everywhere