United Rentals is the world's largest equipment rental company. It principally operates in the United States and Canada, where it commands approximately 15% share in a highly fragmented market. It serves three end markets: general industrial, commercial construction, and residential construction. Like its peers, United Rentals historically has provided its customers with equipment that was intermittently used, such as aerial equipment and portable generators. As the company has grown organically and through hundreds of acquisitions since it went public in 1997, its catalog (fleet size of $21 billion) now includes a range of specialty equipment and other items that can be rented for indefinite periods.