... festival,foods,animal,plants,politeness and so on.3. Every unit has the contents as Story,Words,sentences,let' ... the internet and easy play by the pen.3. Every page of the OID book has printed a record ... sound, it is very useful for children to learn language.specification:1. OID Head, use sonix 4th generation OID ... . Battery, 300 mah high capacity lithium battery. English Language Book With Talking Pen