This information is provided by Underwriter Laboratories Inc. (UL). In the lightning protection field, UL has been serving home and building owners since 1908. Today, UL has a large number of trained lightning protection field representatives located throughout the United States. UL inspects sites ranging from cow barns to missile silos, from golf course shelters to high-rise building systems. In fact, some of the most famous buildings in the world are protected by UL Master Labeled lightning protection systems, including the White House, the Sears Tower and the Washington Monument.