CARBON BAG FILTER MEDIA: Easy-to-use bags contain Black Diamond® Premium Activated Carbon. FOR CHEMICAL FILTRATION: Removes discoloration, s and impurities in aquarium water. COMPATIBILITY: Fits all Marineland® C-Series and Magniflow¢ Canister Filters Rite-Size¢ S, T and X. REPLACE MONTLY: Carbon deactivates with use; for best results, change Marineland Premium Activated Carbon Bags monthly. MARINELAND FILTRATION PRODUCTS: Count on Marineland brand for the most reliable, technically advanced aquariums and accessories on the market.