Keep Water Clean: Water filters remove odors and smells from the water, keep it fresh, ensure consistently high water quality, and create a healthy, thriving aquarium that keeps your fish healthy at all times. High-quality material: The aquarium filter plate is made of high-quality filter cotton and activated carbon, which has good water absorption, good air permeability, strong cotton texture, soft touch, and safe and durable use. Reusable: The aquarium filter pad is easy to clean, you can use the aquarium filter for fish and rocks again and again, and it is also easy to install without any tools. Easy to replace: The filter cartridge is easy to use, just rinse it with cold water, remove the toner and insert it into the filter slot to replace it in seconds. Application: The size is 135 x 56 mm, 4 pieces in total. Please replace the filter element every 2 to 4 weeks if necessary. Suitable for saltwater tanks, freshwater tanks and aquariums, etc., ensuring clean and clear water. Note: