What gas is a widget filled with in can of beer?

Here's how it works:

* Nitrogen gas is forced into a small, plastic sphere called a widget inside the can.

* When you open the can, the pressure inside drops, causing the widget to rupture.

* This releases the nitrogen gas, which creates a creamy head and a smoother, more cascading pour, similar to what you'd get from a draught beer.

Widgets are used to improve the texture and taste of certain styles of beer, like stouts, porters, and some lagers.