---
title: bLength
framework: usbdriverkit
role: symbol
role_heading: Instance Property
path: usbdriverkit/iousbinterfacedescriptor/blength
---

# bLength

The size of this descriptor in bytes.

## Declaration

```occ
uint8_t bLength;
```

## See Also

### Accessing the Descriptor Properties

- [bDescriptorType](usbdriverkit/iousbinterfacedescriptor/bdescriptortype.md)
- [bInterfaceNumber](usbdriverkit/iousbinterfacedescriptor/binterfacenumber.md)
- [bAlternateSetting](usbdriverkit/iousbinterfacedescriptor/balternatesetting.md)
- [bNumEndpoints](usbdriverkit/iousbinterfacedescriptor/bnumendpoints.md)
- [bInterfaceClass](usbdriverkit/iousbinterfacedescriptor/binterfaceclass.md)
- [bInterfaceSubClass](usbdriverkit/iousbinterfacedescriptor/binterfacesubclass.md)
- [bInterfaceProtocol](usbdriverkit/iousbinterfacedescriptor/binterfaceprotocol.md)
- [iInterface](usbdriverkit/iousbinterfacedescriptor/iinterface.md)