The innovative EasyCrystal Filter Pack 250/300 is suitable for both the EasyCrystal Filter 250 and the EasyCrystal FilterBox 300. With its intensive mechanical and biological filtration, the filter cartridge ensures crystal clear, healthy water. The double layered Filter Floss Pads with a large surface area reliably remove even the tiniest particles. White side = coarse pre-filter, green side = fine filter. Suitable for the Tetra Peppa Pig and Tetra Finding Dory Aquariums.