Model number: GTS-032-17 Intelligent car light controller senses weak light, small car light with auto light; it senses darkness, large car light auto light. With high sensibility and one second operated time. Car go through tunnel and cellar, large and small light auto light. Suitable for all kinds of vehicles. Switch the switch to "MANUAL" to close auto function, you can use manual light control system. With the select function for polarity of power voltage, you can choose positive or negative power output as your desire. 20pcs/Ctn, Measurement:1.27'