Features: Efficient Aquarium Water Purification: Our multi porous active carbon filter box effectively removes impurities and harmful substances, restoring clear water conditions in fish tanks. Durable plastic construction with water resistant active carbon layer ensures long time performances for continuous water environment optimization. Ideal for freshwater/saltwater aquarium enthusiasts want professional filtration for their fish pet' habitat maintenance. Perfect for eliminating yellow and maintaining better water parameters for home/office aquariums up to 100 gallon capacity. Easy installation design integrates seamlessly with most filtration, reducing maintenance frequency while promoting fish health through superior absorption. Specifications: Component: Plastic, active carbon Size: approx.11.5x11x11.50cm/4.53x4.33x4.53inch Quantity: 1pc or 2pcs Package Includes: 1pc Water Purifying Filter Box or 2pcs Water Purifying Filter Box note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind before you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color.