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

# IOUSBDeviceQualifierDescriptor

The structure for storing a USB device qualifier descriptor.

```
struct IOUSBDeviceQualifierDescriptor;
```

## Overview

For information about this descriptor, see section 9.6.2 of the USB 2.0 specification at <http://www.usb.org>.

## Topics

### Getting the Descriptor Properties

[`uint8_t bLength;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bLength)

[`uint8_t bDescriptorType;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bDescriptorType)

[`uint16_t bcdUSB;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bcdUSB)

[`uint8_t bDeviceClass;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bDeviceClass)

[`uint8_t bDeviceSubClass;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bDeviceSubClass)

[`uint8_t bDeviceProtocol;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bDeviceProtocol)

[`uint8_t bMaxPacketSize0;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bMaxPacketSize0)

[`uint8_t bNumConfigurations;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bNumConfigurations)

[`uint8_t bReserved;`](/documentation/USBDriverKit/IOUSBDeviceQualifierDescriptor/bReserved)


---

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)