UV sterilization wave band is mainly between 200nm and 300nm, the band of 253.7nm is the strongest to sterilize. When all kinds of bacteria and virus in water or air go through the UV rays (253.7nm) Irradiation area, UV rays penetrate microbial cell membrane and nucleus, destroy the molecular link of DNA or RNA, which then kills all bacteria and virus in the water or air without using any chemicals or drugs. UV sterilization technology is the latest disinfection technology, which sprung up at the end of 1990s.