Description: Sponge filter provides both mechanical and biological filtration. Aerobic bacteria colonize the sponge, providing a bacterial substrate to facilitate the nitrogen cycle. In addition, the sponge traps larger waste particles, mechanically cleaning the water. Features: Easy to split and clean. Reduce noise from air pump and consume lowest wattage. This mini filter box is ideal for small aquariums, does not occupy the place, the effect is obvious. Without separate electricity, with a single-hole pump can be driven. Triple filtration system - filter cotton, quartz sand, activated carbon. Easy to operate, received air pump outlet, directly into the tank to use. Triple effective serial filtration: Sand can block a large number of particles in the water Sponges can adsorb residual material Activated carbon makes water more clear The fresh air blown by the bubble stone will bring clean water and create a healthy environment for your fish. Specification: Condiiton: 100% Brand New Color: White Material: Plastic Small Size: (Dia.) x (H) 7.5 x 11cm / 2.95" x 4.33" (appr.) Big Size: (Dia.) x (H) 7.5 x 14.5cm / 2.95" x 5.71" (appr.) (Optional) Package Included: 1 x Corner Filter Notice: 1. Please allow 1-3cm error due to manual measurement and make sure you do not mind before ordering. 2. Please understand that colors may exist chromatic aberration as the different placement of pictures. 3. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. .