NEWS – These pens would be a perfect gift for the budding spy or secret agent in your family. The pens are filled with ink that’s only visible under UV light. Luckily, the pens’ caps have a UV light source in them, so the message can be quickly decoded as soon as it’s passed over.
The set comes complete with two invisible-ink pens with UV-light caps, with batteries included. The Secret Message Invisible Ink Pens Pkg/2 is $5.99 at The Container Store.