The AquaFX Barracuda 4-Stage RO/DI Replacement Filter Set is designed to ensure the purity of water for saltwater aquariums, reducing impurities and contaminants. It includes a sediment filter to remove particulates down to one micron in size, ensuring that no large particles pass through your system. Additionally, it features a chlorine guzzler carbon block filter which eliminates harmful chemicals like chlorine from your aquarium's water supply. The set also comes with a mix-bed DI resin filter that indicates the condition of its internal resin and can be refilled for extended use, providing highly purified water suitable for delicate reef environments.