... ,2. Its permanent UV ink is invisible to the naked eye, and it’s only visible under UV ... to detect, identify, and return stolen properties in the event of a burglary,4. Label your mobile phone ... LED light,7. Ideal as promotional gift.Specifications1. Invisible pen, OEM accepted 2. Ideal as promotion gift 3. ... valuables.3. Write on any surface with the invisible ink pen! Then view it with a black light ...