... books and become the basic audio products withe e pen. Talking pen for the sound books "Preschool Sound Book " ... earphone or external deviceSpecial Functions(unique in Maliang e-pen) 1. DIY sound sticker, parents can easy record ... sound, it is very useful for children to learn language.specification(P1,P2,P3,P4,P6):1. ... 3.5 mm standerd eraphone slot;7. Battery, 300 mah high capacity lithium battery.