Fluval Plastic Cross Rim Adapter for External Filter Vinyl Tubing Cargo carrier feeding bowl Fits Fluval 304, 404 external filter models A210, A215 Allows for minimal reduction in water pressure, hard plastic rim adapter simply hangs on the rim of the tank, with fittings for attaching hoses Measures 3-inch length by 3-1/2-inch width by 2-1/2-inch height