This pen will bring lots of surprises to your daily life. It can write on most surfaces such as T-shirts and paper. But the words will disappear because it features invisible ink. After you illuminate it with the UV-light which is on the pen cap, you will surprisedly find that the words appear as you have written. It's perfect for currency checking, kids game, transfer, etc. Features - Color: Blue. - Material: ABS. - Size: Approx. 13.3 x 1 x 1cm/ 5.2 x 0.39 x 0.39 inch (LxWxH). - Write invisibly , security markings etc. and only when you shine the on the message you will reveal behind. - With installed in the don't need to buy a spare light, which also comes with button battery in it, convenient to use. - Brings you a variety of fun activities. - Suitable to write on most surfaces such as T-shirts, paper and more. - Small size make it portable to carry, can be used in schools, companies, banks etc. - It also can be used for currency checking. Package list: 2 x Invisible Ink Pen