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  "title" : "Characteristic Units"
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# Characteristic Units

Descriptions of the units of a characteristic.

## Discussion

Expect to find one of these values in the [`units`](/documentation/HomeKit/HMCharacteristicMetadata/units) property of a characteristic’s metadata.

## Topics

### Parts Per Total

[`let HMCharacteristicMetadataUnitsPercentage: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsPercentage)

The unit of the characteristic is a percentage.

[`let HMCharacteristicMetadataUnitsPartsPerMillion: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsPartsPerMillion)

The unit of the characters is parts per million.

### Temperature

[`let HMCharacteristicMetadataUnitsCelsius: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsCelsius)

The unit of the characteristic is celsius.

[`let HMCharacteristicMetadataUnitsFahrenheit: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsFahrenheit)

The unit of the characteristic is fahrenheit.

### Time

[`let HMCharacteristicMetadataUnitsSeconds: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsSeconds)

The unit of the characteristic is seconds.

### Light

[`let HMCharacteristicMetadataUnitsLux: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsLux)

The unit of the characteristic is lux (that is, illuminance).

### Mass

[`let HMCharacteristicMetadataUnitsMicrogramsPerCubicMeter: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsMicrogramsPerCubicMeter)

The unit of the characteristic is micrograms per cubic meter.

### Rotation

[`let HMCharacteristicMetadataUnitsArcDegree: String`](/documentation/HomeKit/HMCharacteristicMetadataUnitsArcDegree)

The unit of the characteristic is the degrees of an arc.


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