1、​Pneumatic filtration principle, the flow of water is generated by the air flow to generate suction, which is water filtered through the filter plate to purify the oxygen while filtering the water quality.​ 2、Activated carbon filter plate, effectively filter harmful substances and fine suspended matter in the water, remove the odor in the water, keep the water body clean.​ 3、With refined bubble stone, can increase the solubility of oxygen in water.​ 4、Combined design, tool-free disassembly, simple and convenient, you can arbitrarily splicing the filter box to suit different sizes of fish tanks.​ 5、Slim body, does not take up space, with powerful suction cups and hooks, can be fixed on the aquarium wall, more convenient.​ Features: Pneumatic filtration principle, the flow of water is generated by the air flow to generate suction, which is water filtered through the filter plate to purify the oxygen while filtering the water quality. Activated carbon filter plate, effectively filter harmful substances and fine suspended matter in the water, remove the odor in the water, keep the water body clean. With refined bubble stone, can increase the solubility of oxygen in water. Combined design, tool-free disassembly, simple and convenient, you can arbitrarily splicing the filter box to suit different sizes of fish tanks. Slim body, does not take up space, with powerful suction cups and hooks, can be fixed on the aquarium wall, more convenient. Specifications: Product Shell Material: ABS Product Color: Transparent gray Product Size: Filter 10: Approx.19.3*10.6*2.2cm/7.6*4.2*0.9inches Suitable for 30-40cm/11.8-15.7inches fish tank Applicable water: Approx.10-20L Filter 20: Approx.19.3*17.8*2.2cm /7.6*7.0*0.9inches Suitable for 40-60cm/15.7-23.6inches fish tank Applicable water:Approx. 20-35L Package List: 1* Pneumatic Filter Note: The product itself has no power and needs to be used with the air pump. The air pump needs to be purchased separately by the customer.