CPF2000U is a compact low pressure filter Ideal for use in a Medium to Large Pond Systems. Includes a 13 Watt UV Clearifier. Detachable Hose Assembly Module Allows Quick Shutoff and easy Disconnection of Hoses for Faster, Easier Filter Maintanance. Reusable Biological and mechanical Filtering Material. Heavy Duty Weather Resistant ABS Plastic Housing Can Be Buried for Inconspicuous Installation. Max Pump Size to use is 1800 GPH. Tubing size; Inlet: 1″ ID Outlet: 1″ ID