Rectangular connectors are electrical connectors used to connect the wires of a device to its circuit boards. These circuits, commonly known as header sockets, female sockets, or receptacles, are designed for different specific applications and can be found in a variety of shapes, sizes, and materials. 851-43-021-20-001000 is a type of rectangular connector. Its application field and working principle are explained as follows.The 851-43-021-20-001000 is a two-power level horizontal header. It is a standard surface-mount application that utilizes two signal power levels, 20 and 28, and provides a secure, space-saving connection in very small applications. It features a durable construction and a mid-shell guide that ensures positive support for mating components during the soldering process. It is ideal for use in board-to-board connections such as narrow header boards, LED illumination circuits, and memory sockets.The 851-43-021-20-001000 can be described as a two-piece connector, with a male connector and a female connector. The male connector is composed of two AC insulation test power levels (20 and 28). The female connector is composed of one power level. The two connectors are connected together using a compression tool, which applies a mechanical force to the parts to ensure that they are securely fastened together.The 851-43-021-20-001000’s working principle is based on the principle of electrical connection. When the male and female connectors are connected, an electrical connection is established between the two sides. This connection is transmitted through the spring contacts of the male and female connectors, allowing an electrical current to flow between the two components. The current flow can then be regulated by using the current adjustment screw on the male connector.In addition to its electrical connection capability, the 851-43-021-20-001000 has several other features. It is UL, CSA, and RoHS listed, meaning that it has been tested and proven to meet rigorous standards in terms of safety and performance. The 851-43-021-20-001000 is also designed to be lightweight and compact for maximum space saving, as well as to be reliable and durable.The 851-43-021-20-001000 is a versatile and reliable rectangular connector that is suitable for a variety of applications. Its comfortable design, durable construction, and adjustable power levels make it an ideal choice for securing tight connections in demanding environments. Furthermore, its UL, CSA, and RoHS listing makes it a safe and reliable choice for all of your electrical connections.