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.spy gear for kidsWidely Applications - 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! You can easily host a kid's birthday party favors stocking stuffer, treasure hunt,escape room,or classroom activity complete with invisible ink clues!Great Gift for Fun Party Favors - This invisible Spy Pen comes in a pack of 7 and can write your secret in the sticky note.Parents can buy it for their kids party at home. Kids love using this kind of pen to keep their secret and play detective spy games. Schools, teachers can buy it for students for a school activity. Add it for any surprise gift bag or as a kids stocking stuffers.Package includes -7 invisible magic pens with built-in UV lights. Batteries included and installed.they each had a pull tab to save battery life. Pens will be available in different colors to keep the activity exciting.Be careful with small items: children over 3 years.Buy with Confidence - we consider our customers as our top priority. Please contact us if there is any problem.(Note: The ultraviolet light visible to the naked eye is light blue-violet.)Kids will love these spy pens in the exciting spy activities. They can use the pen to keep their secrets and play detective spy games which can bring you an amazing variety of fun activities.