<!--
{
  "availability" : [
    "iOS: 12.5.0 - 27.0.0",
    "iPadOS: 12.5.0 - 27.0.0",
    "macCatalyst: 12.5.0 - 27.0.0"
  ],
  "documentType" : "symbol",
  "framework" : "ExposureNotification",
  "identifier" : "/documentation/ExposureNotification/ENExposureInfo/attenuationValue",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "Exposure Notification"
    ],
    "preciseIdentifier" : "c:objc(cs)ENExposureInfo(py)attenuationValue"
  },
  "title" : "attenuationValue"
}
-->

# attenuationValue

The attenutation risk level value for the exposure.

```
var attenuationValue: ENAttenuation { get }
```

## Discussion

Because attenuation can vary over a specific exposure event, the attenuation risk level value is calculated by weighting attenuation risk level values based on their durations during the exposure event.

The attenuation risk level values are configured with [`attenuationLevelValues`](/documentation/ExposureNotification/ENExposureConfiguration/attenuationLevelValues).

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)