Features: Aquarium PreFilter Sponge,Fish Tank PreFilter Sponge，Fish Tank Inlets Cover，For Prevent Small Fish Shrimp Being Sucked,Cuttlefish tank water inlets protective cover, anti-suction small fish and shrimp water pipe, anti-shrimp net cover, filter protective cover Water inlets protection cover to prevent small fish and shrimp from inhaling and isolating impurities Intercepts small fish and shrimp to prevent loss Meticulously filtration to reduce dirt deposition in water pipes Cotton hole cultivation of nitrifying bacteria Specifications: Material:sponge Size:Approx. 10mm/0.39in,15mm/0.59in,20mm/0.79in Color:black Package Includes: 1xAquarium PreFilter Sponge note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color of the item.