Essentials of HSK is a series of exercise books prepared for those who are going to take the elementary and intermediate HSK test (from Band 3 to 8). It is also one of the most intensive exercise books covering most of the language points with detailed explanations. The exercise books are comprised of four volumes: listening, grammar, reading, and comprehensive exercises. Each book contains eight sets of special intensive training testing exercises and two sets of simulated tests with detailed expanations.