Public Storage is a real estate investment trust (REIT). The Company's principal business activities include the ownership and operation of self-storage facilities, which offer storage spaces for lease, generally on a month-to-month basis, for personal and business use, ancillary activities, such as merchandise sales and tenant reinsurance to the tenants at its self-storage facilities, as well as the acquisition and development of additional self-storage space. The Company's segments include Self-Storage Operations, Ancillary Operations, Investment in PS Business Parks, Inc. (PSB) and Investment in Shurgard Europe. As of December 31, 2016, the Company had direct and indirect equity interests in 2,348 self-storage facilities (with approximately 154 million net rentable square feet) located in 38 states in the United States operating under the Public Storage name.