Please pay attention to the two independent buttons at the back of the product that allow you to select either or both "Patting" and "UV Thermal Sterilization" modes. Also, equipped with a pair of photo sensors and a micro-movement switch, when the 3-in-1 Anti-Mite UV Sterilising Cleaner leaves the target surface, the UV sterilisation tube and the PTC thermal system will be automatically switched off to guarantee safety.