The innovative EasyCrystal Filter Pack C 250/300 is suitable for both EasyCrystal Filter 250 and EasyCrystal FilterBox 300. With its intensive physical biological and chemical filtration, the filter cartridge ensures crystal clear, healthy water. Fast, clean replacement: No need to rinse the filter medium, no more wet hands! Important: The filter cartridge must be placed into the filter with the green side facing towards the front of the unit.