This part of ISO 14469 applies to compressed natural gas (CNG) vehicle nozzles and receptacles, constructed entirely of new, unused parts and materials for which there is a demand, in particular for large CNG urban buses of refuelling times equivalent to those of urban buses driven by conventional diesel engines. The proposed connector, size 2, offers a larger cross section than the connector in accordance with ISO 14469-1 and, therefore, permits refuelling of the vehicles within significantly shorter time periods. Studies have shown that the proposed connector, size 2, offers more than twice the mass flow of the connectors specified in ISO 14469-1. CNG fuelling connection nozzles consist of the following components, as applicable