Description: Write Your Secret Message: This magical invisible ink pen will write your secret message. Once your secret message has been written with this invisible ink pen, wait a few seconds to shine the light from the pen's cover and reveal the secret of the secret message for kids INVISIBLE INK PEN: Harmless and tasteless ink, healthy toy for your kids! Smooth and colorful disappearing inks on t-shirts, paper, skin and any surface! Permanent but washable! Great Gift for Fun Party Favors: Package includes: 3 x invisible magic pens per with built-in UV lights. Batteries included and installed.they each had a pull tab to save battery life. keep the activity exciting.Be careful with small items: children over 3 years. Colors are highly pigmented and vibrant which are last against fading, and blend beautifully for added dimension to your artwork, easy-to-see colors make your highlighted text easy to read. It can be used for studying, drawing, sketching, coloring, underlining and so on. Specification: Material: Plastic Size: 15cm/5.91 inch Package Includes: 3 Pieces Invisible Ink Pen