TroyTec HD0-400 offers a variety of products to ensure your success a certification exam of your choice. These products include study guides, Questions and Answers and in some cases (Cisco and Microsoft exams), Realistic Labs. The Questions and Answers include the document containing the questions and answers along with explanations in many cases and testing engine that allows you to practice the questions in simulated exam environment. Using this facility you are in effect trying out the actual tests and the exam papers that you would face in real life.