<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (September 2010) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (September 2010) (Learn how and when to remove this template message) </Td> </Tr> <P> 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, approximately 3 cm in diameter (similar in appearance to table tennis ball, but smaller) with at least one small hole and a seam . The "rocket widget" is found in bottles, 7 cm in length with the small hole at the bottom . </P> <P> Draught Guinness, as it is known today, was first produced in 1964 . With Guinness keen to produce draught beer packaged for consumers to drink at home, Bottled Draught Guinness was formulated in 1978 and launched into the Irish market in 1979 . It was never actively marketed internationally as it required an "initiator" device, which looked rather like a syringe, to make it work . </P>

Why do cans of guinness have balls in them