The key criterion is the intended end-use: a glass tube specifically designed and shaped for use as a fluorescent or other electric lamp envelope, imported without fittings, falls under heading 7011. General-purpose glass tubing not dedicated to lamp manufacture classifies under other glass headings. Documentation of the intended application and the tube's dimensional specifications supports correct classification.

LED modules typically use glass or plastic lenses and diffusers rather than traditional sealed envelopes, and those components generally classify under headings for optical elements or parts of lamps rather than under 7011. However, a glass outer envelope designed to retrofit or enclose an LED assembly may qualify here if it meets the open-envelope, without-fittings criteria. A binding ruling is advisable for novel LED packaging formats.