Tube for 1600 and 1650 Brine Valve Piston Assembly on fleck 2510 Valve, with out Nuts, Ferrules, or Inserts.They can be purchased separately ( SEE related product = Nut used on 1650 Brine Valve Assembly GFN 19625 ).Or for using with brass 60029 brine valve piston assembly, 3/8" nuts ( 10329 ), 3/8" brass inserts ( ( 10332 ), and plastic ferrule /sleeves ( 10330 ) sold SEPARATELY.