iShares U.S. Oil Equipment & Services ETF (the Fund), formerly iShares Dow Jones U.S. Oil Equipment & Services Index Fund, is an exchange-traded fund (ETF). The Fund seeks investment results that correspond generally to the price and yield performance of the Dow Jones U.S. Select Oil Equipment & Services Index (the Index). The Index measures the performance of the oil equipment and services sector of the United States equity market, and includes companies that are suppliers of equipment or services to oil fields and offshore platforms, such as drilling, exploration, engineering, logistics, seismic information services and platform construction. The Fund invests in a representative sample of securities included in the Index that collectively has an investment profile similar to the Index. Due to the use of representative sampling, the Fund may or may not hold all of the securities that are included in the Index. The Fund’s investment advisor is BlackRock Fund Advisors.