100 percent Assured: If you are not satisfied for any reason you can return the water purifier cube for a full refund. We offer a 30 day money back Assured. Specification: Item : Automatic Cleaning Water Filter, Material : New Filtration Material Color : Black Product Size : 10x10x10cm 3.94x3.94x3.94in Attentions: 1. Rinse it with clean water before use, and then put it in fish tank for use. 2. When placing the filter block, be sure to put the filter hole to the direction of the water flow 3. If there is fish medicine (except use for water conditioning), please take out the filter cube and put it into use after the fish recovers health. 4. Due to the porous honeycomb design of filter, there may be some chipping or detachment of the edges when receiving the goods. This is normal and does not affect its function. Pls make sure you do not mind before purchasing. Package Includes: 1 x Water Purifier Cube Filter Note: Please allow 1 3cm (0.4 1.18 inch ) difference due to manual measurement and slight color variation for different display setting. Thank you for your understanding, nice day!