An Attenuator is a passive optical device that reduces the amplitude or power of a signal without distorting its waveform.
The in-line and variable attenuators are patchcord style and can have any style connector applied to each fiber end. Attenuation occurs about mid-span within the fiber. The fixed attenuators are approximately the size of a connector with a ferrule on one side and a port to accept a connector on the other side. (male/female). These are used in the receive port of equipment. The bulkhead attenuators are approximately the size of 2 mating sleeves put together end to end. They accept connectors on both ends (female-female).