---
title: kHIDUsage_Button_21
framework: Kernel
role: symbol
role_heading: Enumeration Case
platforms: [macOS 10.15+]
path: kernel/1641426-anonymous/khidusage_button_21
---

# kHIDUsage_Button_21

## Declaration

```occ
kHIDUsage_Button_21 = 0x15
```