"Specially designed aquarium ultraviolet sterilizer maximizes UV exposure in a compact, easy-to-install unit. Water traveling through the revolutionary ""Turbo-Twist"" flow design is exposed to three times more germicidal UV light than in conventional UV sterilizers. The result is clean, crystal clear aquarium water. Multifunctional UV sterilizers can be installed in-line or as a hang-on unit. Simply connect to a water pump, powerhead, or on the return line of a canister filter. Includes PL-type compact fluorescent UV Lamp and hang-on-tank bracket, and barbed fittings. For fresh and saltwater use."