UV pen with invisible ink
Is new way to get your math formulas and other notes Hidden.
It works very cool
all you need to do is grab our pen and start writing your notes on the prepare
you wont be able to see what are you writing right away.
To see your content you need to use UV light to reveal your notes , the UV light is on top of the pen.
Package comes with
1X UV pen with invisible ink
3X Extra battery’s