Public Storage (the Trust) is a real estate investment trust (REIT). As of December 31, 2012, the Trust's principal business activities included: Domestic Self-Storage, European Self-Storage and Commercial. The Trust acquires, develops, owns, and operates self-storage facilities which offer storage spaces for lease, on a month-to-month basis, for personal and business use. It is a owner and operator of self-storage facilities in the United States. It has direct and indirect equity interests in 2,078 self-storage facilities (132 million net rentable square feet of space) located in 38 states within the United States operating under the Public Storage brand name. The Trust has a 49% equity interest in Shurgard Europe, with an institutional investor owning the remaining 51% interest. It has a 41% equity interest in PS Business Parks, Inc. (PSB), which owns and operates 28.3 million net rentable square feet of commercial space.