Explanatory notes
… (a) Tubes, pipes and hollow profiles, of heading 73.03, 73.04 or 73.06 . (b) Tube or pipe fittings of iron or steel ( … The provisions of the Explanatory Note to subheadings 7304.11, 7304.19, 7304.22, 7304.23, 7304.24 and 7304.29 …