4-in-1 Installation: Our small aquarium filter can be installed in 4 ways (see picture for details). It can be used as a water filter to clean impurities in the aquarium or as an oxygen pump for the water basin. Use the air hose to increase water oxygen and create a healthy environment. 300 L/H Adjustable Water Flow: The adjustable design helps to adjust the water flow rate. The oxygen hose is also equipped with an airflow control valve. Rain/Waterfall Design: The water spray mode presents a beautiful rain/waterfall scene. Note: Avoid excessive water flow, which can affect the life of the fish. Easy to Assemble and Clean: The aquarium filter pump is equipped with a suction cup, allowing you to attach it to the wall and bottom of the aquarium. The filter element can be easily disassembled and assembled. A small brush included in the delivery helps you easily clean the inside of the spray bar. Important note: the minimum water level is not less than 5 cm and the suction cup can be attached to the glass surface. Check and clean the filter components regularly; once a month is recommended. The filter performance will be better after cleaning.