ZYS-02B Photocell is a lighting switch control device comply with UL773 and ANSIC136.41 standard,twist-locked installed in street lamp, courtyard lamp and other lighting lamps for automatic switch control. This type of photo control can detect the ambient brightness to control the switch function of lamps. Wide voltage input, widely used in power grid standards around the world. In addition, it has different switching brightness threshold and delay characteristics, which can avoid the influence caused by lightning at night.