There you have it — a bootable copy OS X Mavericks on USB Flash Drive that can be used to install, upgrade, and/or troubleshoot compatible Apple computers.

Having an independent bootable USB drive or SD Card also makes sense in case you want to install Mountain Lion on multiple computers without having to download it time and again.

How to make your own bootable OS X 10.11 El Capitan USB install drive Setting up lots of Macs? Want an offline installer? Here's how to roll your own.

How to make your own bootable macOS 10.12 Sierra USB install drive You'll need a Mac, an 8GB USB drive or SD card, and a little patience.