【3 in 1 function】 Water change: built-in double airbags, atmospheric cavity, good resilience, effortless operation Washing and sand raking: aquarium siphon with 3D filter basket net, protect your fish from love and the fine gravel of the aquarium suction. Suction: aquarium gravel vacuum cleaner equipped with a duckbill suction inlet attachment, and it is easy to suck the excrement 【Easy to use】 Press the siphon switch, you can stop pushing once the inlet tube part is full of water and water continuously flow out from the outlet pipe. Check whether it will be automatically. If not, keep pushing it. operate until the water flows out automatically. Small debris will be washed away by the current. Please note that the water outlet must be at least 20 inches lower than the inlet when in use