The two-hole line on the aviation head is the power cord of the credit card machine. Brown is positive and blue is negative. Find the constant fire power cord on the car, connect positive to positive, negative to negative. If there is a terminal plug on the car, please check whether the positive and negative of the terminal plug are correct to avoid burning the car insurance. The red wire in the box is a fuse, which is connected to the positive pole. If you want to connect the fuse, you can connect the fuse yourself.