According to the IAB, the standard skyscraper ad is 160x600 and the wide skyscraper is 160x600. They were named as skyscrapers because of their height on the page. Where banner ads are wide and short, skyscrapers and thinner and taller.
An online advertisement that is taller than the vertical banner. The Internet Advertising Bureau recommends two sizes of skyscrapers: 120 by 600 pixels and 160 by 600 pixels.