CBP applies a functional suitability test: if the part is designed and marketed for use with sound or video reproducing apparatus of 8519 or 8521, and has no significant alternative application, it belongs under 8522. A generic electronic component (e.g., a capacitor or transformer) that happens to be used in such apparatus but is equally suited to other equipment would not qualify. Technical specifications, marketing materials, and the part's physical design are all relevant evidence.

A complete pickup cartridge — the assembly that converts groove movement into an electrical signal — falls under 852210. A replacement stylus needle alone, being a part of the cartridge rather than the cartridge itself, is generally classified under 852290 as a part or accessory. Confirm with the specific article's construction and any applicable CBP rulings.