This category includes rectangular connectors, which are used for connecting two electronic circuits or devices with a rectangular housing. It includes various types such as headers, receptacles, and socket connectors. Excludes circular connectors, card edge connectors, terminal blocks, board to board connectors, crimp and solder terminals, backplane connectors, flexible flat cable (FFC) and flexible printed circuit (FPC) connectors, D-sub connectors, and coaxial RF connectors.