PowerShares Insured California Municipal Bond Portfolio (the Fund) is based on the Merrill Lynch California Insured Long-Term Core Municipal Securities Index (the Underlying Index). The Underlying Index is designed to track the performance of United States dollar-denominated, investment-grade, insured, tax-exempt debt publicly issued by California or Puerto Rico or their political subdivisions, in the United States domestic market and includes approximately 297 securities. The Index is adjusted monthly and its constituents are capitalization-weighted based on their amount outstanding. The Fund invests at least 80% of its total assets in insured municipal securities that are exempt from federal income tax and California state income tax.