terminology. Thus a "male gender changer" might have female connectors to mate two male ends, or male connectors to mate two female ends. Adding to this potential for confusion, some gender changers also combine additional functions such as cross-over pin-outs. Active cables may incorporate embedded systems for communications protocol or logic level changes, which technically makes them "adapters", but this distinction is sometimes neglected in marketing materials or common usage. Examples Coaxial power connector, for low-voltage DC connections A power cord on an appliance terminates in a (male) plug; it connects to a (female) socket in a wall or on an extension cord. Coaxial cables used for video or other high-frequency signals are normally terminated, at both ends, in a connector comprising an inner pin and an outer fixed or rotating shell; these are conventionally reckoned as male. A threaded nut is female and a bolt is male. Connectors for air brake hoses on heavy trucks and railroad equipment use genderless "gladhand connectors". In railroad air brake use, this makes the orientation of rolling stock irrelevant, and is used with the standard North American railroad coupler that connects cars together, also genderless. See also Mating connection Piping and plumbing fittings Screw thread Sex bolt Twistlock – standardized fasteners for shipping containers References Gender in language Electrical connectors Plumbing