Replacement filter media for external filters. This is a universal type (8cm wide) and compatible with many filters. Product Features: Water sparkles with powerful filtration!: Keeps water crystal clear with the dual effect of activated carbon, which strongly adsorbs dirt and odors, and zeolite, which decomposes harmful ammonia. High-performance 3-layer structure: The high-performance 2 types of active ingredients and 3-layer structure, and the "triple filtration room" firmly catch and prevent fine leftover food and debris from escaping. Easy one-touch replacement: Can be easily replaced without getting your hands dirty. The replacement目安 is about once every 2-3 weeks. Great value pack of 5: A pack of 5 for plenty of use. Product Condition: New and unopened. Due to long-term storage, the package may have some scratches or stains, but the contents are not affected.