1.SELFPOWERED SPONGE FILTER: The Cascade Powered Aquarium Nano Sponge Filter is specifically designed for aquariums that house fry, shrimp, and small fish. The two ribbed sponges trap floating debris without sucking up smaller or weaker fish and shrimp. This filter comes with its own power supply, meaning that it doesn't need an air pump in order to operate. 2.GREATER SURFACE AREA FOR BENEFICIAL BACTERIA: The two sponges provide an ideal location for the colonization of anerobic bacteria, creating a nicely established bacterial bed for your aquarium. This sponge filter is great for both freshwater and saltwater tanks. 3.ADJUSTABLE WATER OUTLET: This aquarium filter also features an adjustable water outlet that can either be fully or partially submerged in water. Adjust the water flow in any horizontal direction with the 360° directional nozzle. The water outlet tube also has an adjustable height (2.5' difference). 4.KEEPING THINGS CLEAN: Please rinse both sponges with tap water before initial use. This aquarium sponge filter can be used relatedly. Simply rinse the sponges in a bucket filled with your aquarium's water, and then squeeze them slightly to release extra water. After this process, place each sponge back on the strainer tubes. Never use soap, as the residual soap particles can harm your fish.