Features: brand new and high quality Suppress harmful substances in water, prevent bacterial growth and algae breeding, reduce the prevalence of fish diseases. Independent power switch is safer to use. By ultraviolet irradiation, the DNA of the microorganism is destroyed and its reproductive ability is lost, and most of the algae in the water are killed, thereby restoring healthy water, keep the water clear. Made of high quality transparent glass and plastic materials, waterproof, safe and durable. Can be applied not only for fish tanks, but also for rockery fountains, fish for ponds and aquaculture. Notes: 1. This product can emit effective ultraviolet rays. UV rays have certain damage to the human body. Please do not observe it by eyes; It is forbidden to directly irradiate organisms; 2. It is recommended to turn on the lights for about 2 hours each for time. It is forbidden to turn on the lights continuously for more than 6 hours; 3. The lamp can only be used in the filter for tank, and can not be used directly in the fish for tank, otherwise the fish will be injured or die due to long-term ultraviolet radiation! Package Includes: 1 Piece Aquarium Clean Light with Switch and Plug 2 Pieces Suction Cups Specifications: Material: Plastic, Glass Style: 5W/7W/9W/11W/13W Color: As Pictures Show Voltage: 220V Size (Approx.): Light Tube Diameter 1.9cm/0.75in 5W/7W-Light Tube Length 18.5cm/7.28in 9W-Light Tube Length 22cm/8.66in 11W/13W-Light Tube Length 24.5cm/9.65in Weight (Approx.): 5W/7W-167g 9W-182g 11W/13W-189g note: 1.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!