Invisible Ink Pen, Spy Pen Secret Message Writer with uv Light Magic Marker for Drawing Fun Activity Kids Party Favors and Stock Stuffer - 8 Pack 100% brand new and high quality; Package include: 8 invisible magic pens with built in UV lights. Batteries included and installed. Pens will come in a variety of colors (blue, purple, pink, yellow) to keep the activity exciting. Spy Pen:The ink is invisible after you write with it,unless you light on the cap blacklight to see the secret message perfectly. Flavorless and non-toxic ink, harmless ; It can be wrote on T-Shirts,paper,skin! Permanent but washable! (PLEASE DO NOT use on some special surface, like: glass or smooth plastic film, etc; it will influence the effect, and easily to be erased. Buy with comfidence - QIYO is a professional supplier of invisible ink pen. We consider our clients utmost priority. We promise worry-free warranty and friendly customer service. Contact us for any reason if you are not completely satisfied with our product. We aim to please! This magical invisible ink pen will write your secret message. Once your secret message is written with this invisible ink pen wait a few seconds shine the light from the cover of the pen and REVEAL MYSTERY OF THE SECRET MESSAGE. Perfect for the RSVP&#039;s to wedding invitations. Goody bags for kids apy party, Make a fun party favor. Christmas Party Goodies: Birthday Gifts,Halloween Gifts,Christmas Presents for kids and friends. Even using the UV light to check dollar bills. Can be perfectly used on Skin (Harmless and flavorless ink, healthy for your kids), any kind of paper, cloth, wall,etc. It is best not to use it on the smooth surface, like glass. It will be easily erased. The ink is permanent but washable, you can use the cleaning liquid for completely clean.