Prometheus NEO Metal Hop Up Unit with hop arm + cam for M4/M16 Series AEGsPRO-NEO-M4
Beautiful precision hop up unit from LayLax.
Please note that this hop up unit comes with the C-clip and brass ring (pictured), plus a hop arm, cam wheel and washer (not pictured). It is designed to be used with the thumb wheels and gear etc. from the hop up unit that it replaces.