Widget (beer)
A widget is a device placed in a container of beer to manage the characteristics of the beer's head. The original widget was patented in Ireland by Guinness. The "floating widget" is found in cans of beer as a hollow plastic sphere, 3 cm in diameter (similar in appearance to a small table tennis ball) with a small hole in one side. The "rocket widget" is found in bottles, 7 cm in length with the small hole at the bottom.
Read more about Widget (beer): Background, Method, Development, Beer Glass Widget