---
title: bFirstInterface
framework: usbdriverkit
role: symbol
role_heading: Instance Property
path: usbdriverkit/iousbinterfaceassociationdescriptor/bfirstinterface
---

# bFirstInterface

## Declaration

```occ
uint8_t bFirstInterface;
```

## See Also

### Accessing the Descriptor Properties

- [bLength](usbdriverkit/iousbinterfaceassociationdescriptor/blength.md)
- [bDescriptorType](usbdriverkit/iousbinterfaceassociationdescriptor/bdescriptortype.md)
- [bInterfaceCount](usbdriverkit/iousbinterfaceassociationdescriptor/binterfacecount.md)
- [bFunctionClass](usbdriverkit/iousbinterfaceassociationdescriptor/bfunctionclass.md)
- [bFunctionSubClass](usbdriverkit/iousbinterfaceassociationdescriptor/bfunctionsubclass.md)
- [bFunctionProtocol](usbdriverkit/iousbinterfaceassociationdescriptor/bfunctionprotocol.md)
- [iFunction](usbdriverkit/iousbinterfaceassociationdescriptor/ifunction.md)