Master Lock is the worl's largest importer of padlocks, combination locks and related security products for automotive and outdoor needs including home and yard, contractors, power sports, campus and bike needs. An operating unit of Fortune Brands, Inc., Master Lock Company LLC was formed in 1921 by inventor Harry Soref, and is headquartered in Milwaukee, Wisconsin. In 1973, Master Lock ran a famous Super Bowl ad where one of their locks survived being shot by a sharpshooter, thereby proving its durability, thus the slogan "Tough Under Fire". Master Lock would continue running similar ads during future Super Bowls, spending almost their entire annual marketing budget on the single commercial. Later, Master would incorporate the image into one of the first real-life examples of a blipvert in 1998 - though no harmful physiological effects were reported in viewers.