Sunsun JS-400/600 Aquarium Top Filter has unique resin potting, good insulation performance, no water leakage. Three functions in one, which can increase oxygen, pump water and filter tp let you fish more easily. Super large filter box are made of advanced environmental protection plastic, which is flexible and durable. You can add filter materials by yourself to have a better filtering effect. The bottom bracket is retractable and long, which is suitable for more fish tanks.