The Encyclopaedia Britannica Interactive Science Book: Dinosaurs, Reptiles, Birds is an 80-page, brilliantly illustrated book for people of all ages designed for use with the SD-X Interactive Reader (sold separately). The book is part of a six-book library. The books are available separately and also are sold in sets of three and a set of six.The SD-X Interactive Reader is a battery-powered pen that reads text on the book pages and also offers audio content such as facts and sound effects. The Reader works only with the six Encyclopaedia Britannica Interactive Science Library books. Each book has two hours of audio content.The Encyclopaedia Britannica Interactive Science Book: Dinosaurs, Reptiles, Birds covers millions of years of activity on Earth, starting with the most up-to-date knowledge of dinosaurs and branching into extensive information on creatures that still carry dinosaurs' genetic traces-reptiles and birds. The book is filled with detailed photography, informative charts, and illustrations—all accessible in an enhanced format using the SD-X Interactive Reader. - from Amzon