Chapter 85 covers apparatus whose function is electrical: motors and generators, transformers, switchgear, wire and cable, telecommunications apparatus, semiconductors, lamps and batteries. It shares Section XVI with Chapter 84, and its rules for parts.
The boundary with Chapter 90 is the expensive one. An apparatus that measures, checks or analyses belongs to Chapter 90 even when it is wholly electronic. An apparatus that transmits, switches or supplies stays here. Domestic appliances with a self-contained motor stay at 8509 rather than moving to Chapter 84.
Every number opens on the lines beneath it, down to the eight-digit statistical code.