[Product Specifications] Voltage: 220V Frequency: 50HZ Power: 2W Maximum Flow: 200L/H Maximum Head: 0.45M 1. Suitable for filtering and oxygenating small tanks below 30 cm ! 2. If your tank’s filtering sound is very loud, you can’t sleep well at night . If you stop it , you’re afraid that the fish will be hypoxic . The mute effect of the oxygen pump is not good. Then please choose this one . It is your good helper at night . Note that the maximum diving depth used for the big tank does not exceed 10 cm to allow normal oxygen injection . Let your beloved fish spend the long night !!!!! The big tank cannot be used for filtering , it can only be used as an auxiliary equipment at night !!! The multi-layer biochemical filtration submersible pump sends oxygen from below the water to the aquarium through the intake pipe. The continuous water flow allows oxygen to diffuse to the aquarium with the water flow, and at the same time brings carbon dioxide to the air. The novel design concept is equipped with filtration Cotton and fine dirt will not be missed; strong rubber suction cup is easy to install on the wall of the aquarium.