---
title: kIOMaximumByteCountWriteKey
framework: IOKit
role: symbol
role_heading: Global Variable
platforms: [iOS 16.0+, iPadOS 16.0+, Mac Catalyst 13.0+, macOS 10.2+, visionOS 1.0+]
path: iokit/kiomaximumbytecountwritekey
---

# kIOMaximumByteCountWriteKey

## Declaration

```swift
var kIOMaximumByteCountWriteKey: String { get }
```