CUMMINS ISX, QSX ENGINES – HAS PRE-FILL COVER ON THREADED END – ONCE FILTER IS PRE-FILLED WITH FUEL ON THE INLET SIDE, REMOVE THE COVER BEFORE INSTALLING – FOR NANO-PRO VERSION, USE WF10515

RACOR FUEL SYSTEMS – REPLACES RACOR # R120P – THIS HAS A ONE-PIECE DESIGN W/ DRAIN (NO SENSOR PORT) – ELIMINATES THE PLASTIC BOWL REQUIRED FOR THE RACOR DESIGN – FOR RACOR DESIGN (PLASTIC BOWL REQUIRED), USE 33774 – IF YOU WISH TO ADD A PLASTIC BOWL TO THE WF10021, CAN ADD BOWL PART # WS10003 – REMOVE THE DRAIN FROM THE BOTTOM OF THE FILTER, INSTALL THE BOWL, THEN INSTALL THE DRAIN TO THE BOTTOM OF THE BOWL.