UV (UVC) ray is produced to zap bacteria, viruses, mite and mold. UVC can damage DNA structure of the microorganism. Take virus as example, UV light modifies the DNA structure of viral pathogens life HFMD so that they cannot reproduced and therefore cannot colorize and harm human. This product highly efficient at sterilization, disinfection and odor elimination. You can feel the sunshine after sterilization completed.