Suppress harmful bacteria in water. Prevent bacterial growth and algae breeding. Reduce the prevalence of fish. Keep the water clear. Independent power switch is great for safer use. By ultraviolet irradiation, the DNA of the microorganism is destroyed and its reproductive ability is lost, and most of the bacteria and algae in the water are killed, thereby restoring healthy water. Made of high quality materials, more durable. The tail is made of insulating material to make it waterproof and more secure. The multi-stage sealing ring can be used for diving. The scope of application is not only fish tanks, but also rockery fountains, fish ponds and aquaculture. Wattage: 5W/7W/9W/11W/13W(Optional) Plug Type: US/EU Voltage: 110/220V Body Material: Quartz Glass Lamp Length: 17cm(5W/7W) , 23cm(9W/11W/13W) Cable Length: Approx. 110cm Suitable For Fish Tank Size: Within 60cm(5W), 80cm(7W), 100cm(9W), 120cm(11W), 150cm(13W) Package Included:1*Aquarium Submersible UV Light