Crystal is the internal filter for aquariums that ensures an effective 2-stage filtering action. The first mechanical stage through a sponge captures the waste dispersed in water while the second can be of a chemical or biological type depending on the material you will use inside the special compartment, activated carbon or ceramic material for example.The Crystal filter is supplied complete with activated carbon and support with suction cups, equipped with a Venturi kit that ensures optimal oxygenation of the water. It was designed by Archie & Oscar to prevent dirt from returning to the tub, the water flow is adjustable.Available in various models with different pump flow and head.Cleaning tips: remove dirt and limestone from the impeller and its seat, rinse the sponge with warm running water. If the venturi system does not supply air, the silencer must be cleaned. Size: 16cm H x 5.5cm W x 5.5cm D