7Pcs/set Magic Uv Light Pen Invisible Ink Pen Glow In The Dark Pen With Built In Uv Light For Gifts And Security Marking Product Information Spy Pen:The ink is invisible after you write with it,unless you light on the cap blacklight to see the secret message perfectly. Invisible Ink Pen: Harmless and tasteless ink, healthy toy for your kidsSmooth and colorful disappearing inks on t-shirts, paper, skin and any surface,permanent but washable Exciting Spy Activities For Kids: Kids will love these pens. Kids love using this kind of pen to keep their secret and play detective spy games. Invisible pen brings you an amazing variety of fun activities. From Surprise birthday parties, to revealing a top secret message to their parents or grandparents. Great Gift for Fun Party Goodies:Perfect for wedding invitations; Make a fun party favor; brings you an amazing variety of fun applications.Birthday Gifts,Halloween Gifts,Christmas Presents for kids and friends.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,built-in UV lights. Batteries included and installed. Be careful with small items: children over 3 years. Material:Plastic Note: 1. Due to the different monitor and lighting effect, the actual color of the item may be slightly different from the color shown on the pictures. 2. Please allow 1-3cm error due to manual measurement. (1 inch = 2.54 cm) Thanks for your support :)