8540.91 - Of cathode-ray tubes:

This category, HTS 8540.91, specifically encompasses parts and accessories designed for cathode-ray tubes (CRTs). CRTs are the display technology historically used in televisions and computer monitors, characterized by an electron beam scanning across a phosphorescent screen. Therefore, this classification covers components that are integral to the function and operation of these tubes, such as internal elements or external control mechanisms directly associated with the CRT itself, but not the complete tube unit.

Distinguishing this category from its sibling, 8540.99 ("Other"), is crucial for accurate classification. While 8540.99 covers all other parts of thermionic, cold cathode, or photocathode tubes not specifically identified, 8540.91 is dedicated solely to those parts exclusively used with cathode-ray tubes. This means that if a component is solely manufactured for or exclusively used in a CRT, it falls under 8540.91, whereas parts applicable to other types of tubes within the broader heading 8540 would be classified elsewhere.

The subcategories within 8540.91 further refine the classification based on the specific function or type of part. "Front panel assemblies" likely refers to the glass faceplate and any associated elements that form the front of the tube. "Deflection coils" are critical for directing the electron beam to create the image. Finally, "Other" serves as a residual category for any CRT parts that do not fit the more specific subheadings, ensuring comprehensive coverage of all components dedicated to cathode-ray tube technology.