The reference configuration of a jet fan can be defined as an axial jet fan, complete with a lx diameter silencer at both inlet and outlet, but with no internal pod in either silencer. It includes integral inlet devices to optimize performance only such as conical or bell-mouth inlets, but it does not include the addition of accessories such as guards or screens, deflectors or any devices unique to application. If any appurtenances are included, these shall be clearly recorded.