Oxford Reading Tree Read with Biff, Chip, and Kipper Levels 1-9, 112-book set. Purchased new, with no writing or markings. All books are in near-new condition. Also includes the "The Very Hungry Caterpillar" pen. Simply touch the Oxford Reading Tree series books with the pen to play the audio. These books are popular English learning materials. Designed so that you can naturally acquire English by reading the stories in order from Level 1. This is a truly excellent English learning resource for preschoolers and elementary school students who want to enjoy learning English with their children and acquire natural English expressions used in everyday life. [Product Details] Levels 1-9, 112 books total Details: Level 1 → 13 books Level 1+ → 35 books Level 2 → 12 books Level 3 → 8 books Level 4 → 8 books Level 5 → 8 books Level 6 → 9 books Level 7 → 8 books Level 8 → 2 books Level 9 → 9 books