Where can I buy the glass from the2424milk.com commercial?

In a 2424mik.com commercial, they show a cool looking beverage glass with milk in it. Does anyone know who makes this glass or where I can buy it? It is a normal glass except the middle is skinnier than the ends, kinda like an hourglass. A picture of the glass can be found on their website, 2424milk.com, in the top left corner.