9405.91.40.00 - Chimneys

This HTS category, 9405.91.40.00, specifically classifies "Chimneys" that are parts of luminaires and lighting fittings, or illuminated signs. These chimneys are typically made of glass and serve as a protective or decorative element for the light source. They are distinct from other glass parts of lighting fittings, such as globes and shades (9405.91.20), which may have a different structural function or aesthetic purpose in diffusing or shaping light.

As this is a leaf node, there are no further subdivisions within this specific HTS code. Therefore, the focus for classification under 9405.91.40.00 rests on identifying glass components that are clearly identifiable as chimneys for lighting applications. Classification requires ensuring the item is not intended for other uses and that its primary function is integral to a lighting fixture or illuminated sign, aligning with the broader scope of Chapter 94.