Enhance aquarium filtration with Reaction large-capacity, 4-stage canister filters. Revolutionary canister filters boast greater media-storing capacity so aquarium water comes into contact with more filter media during the initial pass. Combined with a built-in 5W UV sterilizer, you enjoy clean, clear, and healthy aquarium water from a single, space-saving unit. Advanced, high-performance features help ensure high water quality plus quick and easy routine filter maintenance. 5/8" intake and return.