1. Children's Lovers: Children like to use this pen to keep secrets and play detective spy games. Magic pencils bring you a variety of fun activities. Top secret information in a surprise party from her parents or grandparents. 2. A perfect gift: different colors make the event more exciting and interesting. Parents can buy gifts for their children as gifts. Teachers can purchase it for school activities. 3. Harmless and tasteless ink: You can write anywhere: such as T-shirt,paper,skin and any surface. A healthy toy for your child and environment friendly pen. 4. Wide use: Ideal for RSVP wedding invitations. Goody packages for children's spy parties,fun parties,and even use lights to check US dollar bills. Bringing you amazing fun,its great for kids and friends. 5. Best use: When your information is written on the pen,you can see it,but you can see it clearly with the light at the top of the pen. Notice: Please allow 1-3cm deviation due to manual measurement Actual color may be slightly different from the image due to different monitor and light effect Description: Material: Reusable Plastic Size:as shown includes: 4X Ink Pen