Ink : The pen with special ink will gradually fade within 30 minutes after writing, and the books are reusable. Groove : The books are designed with special grooves which can lead your handwriting correct and beautiful! Paper : The paper are thick and durable. Children may take it with them anywhere and paint as they like. Grips : This set contains a pen and a grip with random color. It not only helps correct writing grip posture but also makes the writing more funny. Cute gift packs make kids full of surprises : 4 x Copybooks 1 x Pen holder 10 x Magic pen refill 1 x Aid pencil grips