With two trigger modes and two output modes: 1. You can set two trigger modes (bright trigger and dark trigger) by JMP1 two jumpers: Light trigger mode: when the photo resistor senses the ambient light from a light or no light when the light gradually increased, relay. 1~3; Dark trigger mode: when the photo resistor senses the ambient light from bright to dull gradually weakened to and relay. 2~4; 2. Passive output repay and active transistor drive output. JMP2 jumper settings whether to allow the relay to work, if no relay passive output this feature, you can set the relay does not work to reduce the power consumption of the circuit, jumper disable the relay works in the 2~3 position, jump line cap allows relay at the 1~2 position.