This 5" fine point marker, is loaded with special ink that is only visible under UV light.
Counterfeit Money Bill Detector
It includes a mini LED UV black light with batteries, so you can view your messages.
Kids love them for writing secret messages & notes to each other, students can highlight  text books and still sell the book when they finish their coursework.
You can mark your personal property with your house number and zip code in case of theft.
Push the button to open the UV light for viewing your invisible messages.

Type: Ink Pen
Cover Material: Plastic
Refill Color: White
Size: 13cm x 1.8cm/5.12'' x 0.71'' (Approx.)
Notice: The words written by it can't be erased,it doesn't have 2 heads.

Package:
10 x Invisible Ink Pen

Notes:
The color is sent at random.
Due to the light and screen setting difference, the item's color may be slightly different from the pictures.
Please allow slight dimension difference due to different manual measurement.