Interactive Science Library : The Encyclopedia Britannica 3-Book Interactive Science Library is a captivating and effective learning and entertainment center for people of all ages. The set includes: 1 SD-X Interactive Reader, a battery-powered pen that reads the words on the book pages and offers audio content such as facts, sound effects, and cross-references to other pages in the book. 2 AAA batteries. 3 fact-filled science books from the editors of Encyclopedia Britannica: ANIMALS includes data on invertebrates, amphibians, and mammals. UNDER THE SEA includes information on ancient life, invertebrates, fish, amphibians, reptiles, and mammals. DINOSAURS, REPTILES, and BIRDS includes data on how the mighty creatures of prehistoric times live on today in their crawling and flying ancestors.