Comcast Corporation is a provider of cable, entertainment and communications products and services. The company has more than 21 million cable customers, more than 8 million high-speed Internet customers and more than 1 million voice customers. Comcast is principally involved in the development, management and operation of broadband cable systems and the delivery of programming content. The company's content networks and investments include E! Entertainment Television, Style Network, The Golf Channel, PBS KIDS Sprout, TV One and four regional Comcast SportsNet channels. The company also has a majority ownership in Comcast-Spectacor, whose major holdings include the Philadelphia Flyers NHL hockey team, the Philadelphia 76ers NBA basketball team and two multipurpose arenas in Philadelphia. Brian L. Roberts has been the chief executive officer of Comcast for more than three years. He has been with the media company for over 16 years. Roberts attended the Wharton School of Finance, at the University of Pennsylvania. Comcast Class A common stock and Class A Special common stock trade on the NASDAQ Stock Market under the symbols CMCSA and CMCSK, respectively. Comcast is headquartered in Philadelphia.