● This is a pen that makes writing appear when a light is shined on it. ● The writing is invisible when written with this pen. ● This is a new, unused item, but it has been stored at home for a long time, so please purchase only if you are not concerned about this. ● Due to long-term home storage, the pen may not work. Please do not purchase if you cannot accept this. ● Please purchase if you are not concerned about home storage. ● This is a layman's inspection, so there may be oversights. Please understand this before purchasing. ● If you have any questions or concerns, please comment before purchasing.