About this item [Invisible ink pen]: harmless and tasteless ink, safe toy for children Fill it with the latest upgraded invisible ink, which is really invisible to the naked eye to protect your secrets and mark your personal items. It can be used for t-shirts, paper, skin and more surfaces. [Ultraviolet pen]: The ink cannot be seen after you use it to write, unless you turn on the black light of your hat to see the secret information perfectly. Built in ultraviolet lamp, each pen can display hidden information. [Party Gift]: It is very suitable for RSVP's wedding invitation; A good bag for children's spy party; Have a fun party; Great Godie package entertainment, bringing you a variety of interesting applications. Birthday gifts, Halloween gifts, Christmas gifts for children and friends. [Goodie Bag Fillers]: 6 bright colors to create more exciting and interesting party gifts. It is very suitable for various interesting activities, such as escape room party, birthday party, spy game, treasure hunt game, class party, etc. Please note that it is not suitable for children under 3 years of age and should be used under adult supervision.