<!--
{
  "availability" : [
    "DriverKit: 19.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "USBDriverKit",
  "identifier" : "/documentation/USBDriverKit/IOUSBBOSDescriptor/bDescriptorType",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "USBDriverKit"
    ],
    "preciseIdentifier" : "c:@S@IOUSBBOSDescriptor@FI@bDescriptorType"
  },
  "title" : "bDescriptorType"
}
-->

# bDescriptorType

The type of the descriptor.

```
uint8_t bDescriptorType;
```

## Discussion

The value in this field is always [`kIOUSBDescriptorTypeBOS`](/documentation/USBDriverKit/tIOUSBDescriptorType/kIOUSBDescriptorTypeBOS).

---

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)