TUBE NUT & FERRULE ASSEMBLY FOR 1/4" FUEL RETURN LINES ON MULTIFUEL ENGINES. 

THESE COME ATTACHED TO EACH OTHER, AND THE ORIGINALS ON YOUR TRUCK DID ALSO. ONCE TIGHTENED THEY WILL SEPARATE FROM EACH OTHER AND SEAL AS THEY SHOULD. 

PART # F6538352

TUBE INSERTS ALSO AVAILABLE.