6 Pcs Fish Tank Filter Cartridges, Aquarium Filter Cartridge Replacement, WallMounted Filter Accessory for Fish Tanks, Activated Carbon Materials, Water Cleaning Supplies

This review is for the 6 Pcs Fish Tank Filter Cartridges, with Activated Carbon MaterialsI chose these on the hope that they would fit my Fluval U2 filter, dimensionally they would fit the filter frames, but because these are around 8mm thickness I couldn't use the Sponge and these Carbon Filters togetherHowever they are fine for my generic Amazon tank wall mount filter, it doesn't use any frames, and allows drop in filter padsThese are well made, with an inner plastic frame and wrapped in a cotton mesh, but the inner frame creates hollow cavities filled with Activated Carbon Pellets, so very much an all-in-one filter pad.Measuring around 135 x 56mm, they could be used in the Fluval U2 but without the spongeGood design at a reasonable price, currently £10.59 for 6x filters