Paddy and Mick sitting on a building site, when Mick notices paddy's new flask.
"That's a nice looking flask you have there Paddy" says Mick
"Yes its top of the range" says Paddy proudly
"What does it do then?" says Mick
"It says it keeps hot things hot and cold things cold all day" says Paddy
"So what have you got in there today then Paddy?" asks Mick