Thermos flask

A man goes into a store and sees a shiny object. He asks the clerk, “What is that shiny object?”

The clerk replies, “That is a thermos flask.”

The man then asks, “What does it do?”

The clerk responds, “It keeps hot things hot and it keeps cold things cold.”

The man says, “I’ll take it!”

The next day, he walks into work with his new thermos. His boss sees him and asks, “What is that shiny object with you?”

He said, “It’s a thermos flask.”

The boss then says, “What does it do?”

He replies, “It keeps hot things hot and cold things cold.”

The boss said, “Wow, what do you have in it?”

The man replies, “Two cups of coffee and a coke.”