Wearable electronic devices such as smart rings, smart wristband/bracelet, chest straps or fitness tracker are classified based on their essential functionality.
See also: {augmented_or_virtual_reality_goggles_or_headsets }, {smart_watches} and {smart_glasses}
Some of these devices do not carry out the measurement themselves — heart rate, for example. Instead, the sensors and transmitters they contain relay the relevant signal to a separate device that performs the counting or measuring. In such cases, the device is classified as a part or component of the apparatus that performs the actual measurement.
For instance, a chest strap whose sensors do not measure but merely transmit heart rate signals to a tachometer is classified under heading 9029.90 as a part of a tachometer, tachometers themselves falling under 9029.20. Likewise, a chest strap that transmits its output to a measuring device other than a tachometer — such as a fitness tracker, a bicycle speedometer, a watch or a smartphone — is classified under 9031.90 as a part or component, rather than under 9031.80