UV Pen with invisible ink - a new way to get your math formulas and text notes are hidden to others, but easily readable to you!

How does it work?

All you need to do is grab your pen and start writing your notes on the paper. 
At first, you won't be able to see what you wrote, but then, magic happens! To see what you wrote, just press the button on the pen and the UV light (positioned on the top of the pen) will reveal all your notes! As easy as that!