What is the small device in a beer can?

The small device in a beer can is called a pull tab. It's a small metal piece attached to the top of the can that allows you to open it easily by pulling on it.

Here's how it works:

* The pull tab is connected to a small piece of metal called the "tab opener" that is attached to the can's lid.

* When you pull on the pull tab, it tears away from the tab opener, leaving a hole in the lid.

* This hole allows you to pour the beer out.

Pull tabs are a great invention because they make opening beer cans much easier and more convenient than the old way of using a can opener.