This exciting series highlights eight types of vehicles that militaries around the world use to find, fight, and spy on enemy forces. Each book describes one machine's history, key features, and roles in battle. Each book also includes historic images, a table of contents, fast facts, sidebars, comprehension questions, a glossary, an index, and a list of resources for further reading. Apex books have low reading levels (grades 2-3) but are designed for older students, with interest levels of grades 3-7.