Pin-Indexed Yokes
Pin indexed yoke assemblies are used in medical gas delivery systems. Their purpose is to connect gas cylinders to regulators/other.
Each assembly consists of a yoke block, yoke screw, and pin index system. They're widely used with oxygen, air, and nitrous oxide. The National Fire Protection Association (NFPA), the Occupational Safety and Health Administration (OSHA), and the Food and Drug Administration (FDA) all recommend their application.