Easy To Replace Filter Cartridge Traps Dirt And Contains A Natural Substrate Which Helps To Maintain Healthy Clear Water Between Servicing. Supplied In Packs Containing - 1 New Filter Cartridge 1 Cleaning Pad And 1 Water Treatment Sachet Simply Unclip The Old Cartridge And Fit A New One Every 4-8 Weeks Just Like Taking Out The Rubbish. Service Kit Eliminates The Need To Cut Filter Foam Deal With Messy Carbon And Measure Out Doses Of Water Treatment.