The Rio Micro Pad is a universal filtration media that polishes water on a microscopic level. This versatile, extra fine pad traps micro particles and fine debris, removing them from circulation and producing crystal clear, clean water. Cut to fit a variety of filtration systems to keep your water clean and healthy. Micro water polishing filter pad Universal filter pad - just cut to fit For fresh or saltwater aquatic environments Use in virtually any type of aquatic filtering system, including: Hang On Back filters, Canister filters, Wet and Dry filters, Top filters, Internal filters and Pond filters.The Rio Micro Pad is a tightly woven mechanical filter pad designed for removing fine and coarse free-floating particles from your aquarium or pond, preventing the biological media from becoming clogged.Directions:1. Cut the Micro Pad slightly larger than required.2. Verify that the pad fits and trim if needed.3. Rinse in tap water to remove dust and place in filter.Replace every 4-6 weeks, or when required.