8540.40.10 - Data/graphic display tubes, monochrome; data/graphic display tubes, color, with a phosphor dot screen pitch smaller than 0.4 mm

HTS code 8540.40.10 specifically classifies monochrome data and graphic display tubes, as well as color data and graphic display tubes with a phosphor dot screen pitch measuring less than 0.4 mm. These are specialized cathode-ray tubes designed for the output of visual information from computers and other electronic devices.

This category is distinguished from its siblings primarily by its function and technical specifications. For instance, while other categories within 8540 may cover television picture tubes, camera tubes, or microwave tubes, this heading is narrowly focused on display tubes for data and graphics. The precise specification of a phosphor dot screen pitch smaller than 0.4 mm for color tubes is a key differentiator, ensuring these are higher resolution displays compared to general-purpose television tubes that might fall under a different subheading.

The subcategories within 8540.40.10, namely "Color" (8540.40.10.10) and "Other" (8540.40.10.50), further refine the classification based on the color capability of the display tube. The "Color" subheading captures all color data and graphic display tubes meeting the pitch specification, while "Other" would encompass monochrome variants or any other display tubes that fit the general description but are not specifically color.