The Aqua UV Clarifier is the premium choice for external water clarification. It controls the amount of harmful bacteria in your pond, creating a healthier pond ecosystem. 2 Inch inlet - outlet. Up to 500 gallons. Maximum Flow of 700 gph. 3/4 Inch INLET/OUTLET, 1 LAMP. Unit: 22-1/4 Inch X 4 Inch X 2-1/2 Inch. 6 LBS.(product code: AU00017)