Introducing the Red Sea Reefer Fine Felt Polishing Filter Socks, designed specifically for aquarium filtration. These filter socks are made from 100 micron fine felt, ensuring effective polishing of your aquarium water by capturing fine particles and debris. Each sock measures 4 inches by 10.5 inches, making them suitable for various aquarium setups. The Red Sea Reefer Fine Felt Polishing Filter Socks are perfect for maintaining a clean and clear aquatic environment. With a pack of four, you can easily replace them as needed to keep your filtration system running efficiently. These filter socks are an essential accessory for any aquarium enthusiast looking to enhance water quality and provide a healthy habitat for their aquatic life.