Write Your Secret Message - This magical invisible ink pen allows you to write hidden messages. After writing your message, simply wait a few seconds and use the built-in UV light on the pen to reveal the invisible text. Ideal for kids' spy-themed play and imaginative adventures.Wide Range of Applications - The ink is non-toxic and odorless, making it a safe and fun activity toy for children. The smooth-flowing ink works on paper, clothing, skin, and most surfaces. Ink is permanent until washed off, making it reusable for various activities.Perfect for Parties and Games - Great for organizing kids' birthday party favors, stocking stuffers, treasure hunts, escape rooms, or classroom games with invisible ink clues. Encourages creativity, problem-solving, and interactive play.Great Gift for Kids - This set includes 7 invisible ink pens, each featuring a built-in UV light for revealing messages. Ideal for use on sticky notes and other surfaces. Parents can use them for home activities, while teachers can incorporate them into classroom learning games. A fun addition to holiday gift bags, Easter baskets, Halloween treats, or Christmas stockings.Package Includes - 7 invisible ink pens with built-in UV lights. Batteries are included and installed. Each pen has a protective pull tab to preserve battery life. Pens come in assorted colors to keep playtime exciting.Safety Information - Not suitable for children under 3 years due to small parts. UV light emits a visible blue-violet glow. All UV lights appear purple-blue in color.Fun and Engaging Gift - These spy pens provide hours of entertainment during playdates, parties, or educational activities. Kids love writing secret messages and playing detective games, making this an exciting gift for any occasion.