Kaplan's NCLEX review book is a comprehensive study guide that helps nursing students prepare for the NCLEX exam. The book covers all the essential topics and concepts that are tested on the exam, including medical-surgical nursing, pediatric nursing, mental health nursing, and more. It also includes practice questions and practice tests to help students assess their knowledge and improve their test-taking skills. Overall, Kaplan's NCLEX review book is a valuable resource for nursing students who are studying for the NCLEX exam.