Pin head connectors and female head connectors can be divided into 2.54mm, 2.00mm, 1.27mm, 1.00mm, 0.8mm, etc. according to the spacing. There are single row pins, double row pins, three row pins, etc. according to the number of rows; According to packaging principles, SMT (horizontal/vertical) and DIP (direct/curved) are widely used as universal connecting devices in electronics, appliances, and instruments, mainly for current or signal transmission.