8518.10.40.00 - Microphones having a frequency range of 300 Hz to 3.4 kHz with a diameter of not exceeding 10 mm and a height not exceeding 3 mm, for telecommunication use

This classification specifically covers microphones designed for telecommunication use. These microphones are characterized by a narrow frequency range, typically from 300 Hz to 3.4 kHz, and have stringent physical dimensions: a diameter not exceeding 10 mm and a height not exceeding 3 mm. These specifications are crucial for their integration into compact telecommunication devices.

Distinguishing this category from its sibling, 8518.10.80 (Other microphones), is the precise combination of the defined frequency range and the very small physical dimensions. While other microphones might fall under the broader "Other" category, this particular subheading is reserved for those meeting the strict technical and dimensional requirements for telecommunication applications, often found in telephones, mobile devices, and similar communication equipment.

As this is a leaf node within the HTS, there are no further subcategories. Classification within this heading relies entirely on meeting the precise technical and dimensional criteria outlined in the description. Examples of goods that would fall here include microphone capsules for landline telephones, headset microphones for mobile phones, and other miniature microphones specifically engineered for voice transmission in telecommunication systems.