Description Hide the secret message: This magic invisible ink pen allows you to write your secret message and hide it. Only when you turn on the ultraviolet light can you reveal the secret of the secret information. Comfortable use experience: these practice pens are lightweight and suitable for student writing, and the thoughtful design of magic invisible ink will be favored by children, the pen disappearing blue ink will disappear in 15 20 minutes. What you get: there are 10 invisible ink magic ballpoint pens, you can write your secret on paper safely to meet all your secret needs, you can also share this magic ballpoint pen invisible ink with your family or friends. Party gift choice: Parents can buy them for group activities at home, many children like to use them on Halloween and Christmas to keep secrets, play detective games, hunting treasure, escape rooms and classroom activities. Exquisite workmanship: the material of the invisible ballpoint pen shell is plastic, the metal texture and appearance is quite beautiful The size is 14 cm/ 5.51 inch, which is light and portable, and it is comfortable to hold in your hand and writes smoothly.