Replacement Filter for AQ, EC, SP Series Ionizers - Replaceable Cartridges - EC450, EC550, AQ300, AQ500, AQ700 and Odyssey Replaces the.1M Carbon Filter (ACF-K) and fits all Yi Shan Water Ionizers Fits the EC450, EC550, AQ300, AQ500, AQ700 and Odyssey Models also AntiOxident K3-450 WILL NOT fit Gold Fox Models EP400, EP600, EP800, and EP1000 Ionizers or any Jupiter Ionizers Contains 2 Filter Cartridges 1- Carbon - KDF Cartridge and 1 - Nano Zinc Bacterial Filter Top Inside Diameter opening is 0.5", bottom opening is 0.625" inside diameter, 8" High