Eachine1 Fd585 Magic Invisible Ink Marker Disappearing Secret Message Pen

FD585 Magic Invisible Ink Marker Disappearing Secret Message Pen Paper saving Features: Sign pen with invisible ink. It writes as smoothly as common sign pen with the same color (Blue color)when it is writing. The ink will automatically disappear in 5mins~24h without any remains or signs left. Paper-saving and environmental-friendly. You don't need to worry about wasting your paper when you are practicing your writing and taking some unimportant notes. You can also leave some secret message or important information to some specific person without being discovered. Specification: Color: silver & black Material: plastic Pen length: 14cm Package included: 1 x pen