Features: 1. Strong Sterilization：Fish tank disinfection lamp can kill up to 99.99% of bacteria！UV-C disinfection works by breaking down certain chemical bonds and scrambling the structure of DNA, RNA and proteins to effectively destroy all microorganisms. 2. Disinfection：254nm wavelength light help to remove the green in the fish tank, pond, make it clear.Extremely efficient and time-saving in use in in 30 minutes, which can provide a clean living environment for your fish. This will be the best choice for fish lovers. 3. Easy to Operate：Press the button to control the light, Suitable for Freshwater and Saltwater, suggest that use the light 3-4 hours once in 2-4 days. 4. Superior Silica Glass：Glass products, handle with care, do not shake, it is easy to cause a short circuit.Please Note that this light only clean water green in the water, but can not clean the black precipitate attach on rock and tank. 5. Warm Notice：Please measure the size of your aquarium and compare with the dimension of our product before purchase. Instructions: the best way is using the light in sump tank, if you do not have a sump, may be you can divide the fish tank two part with a Opaque plastic board, use the light in the part which the fish can not reach. But please make sure the water can flow over the plastic board. Specifications: 1. Material: Glass & UV Light Inlet 2. Size: 6.89in,6.89in,8.27in,8.27in 3. Voltage:110-120V/60Hz 220-240V/50Hz 4. Power:5w 7w 9w 11w Caution: 1. We may send you a plug adapter(EU, US, AU, UK,etc) according to your country . If you need another type, please leave a message after ordering or contact us directly. 2. Please double comfirm your local voltage and frequency before you place the order.If not match,the light would not work.