Security ID Pen Anti-theft Permanent Invisible UV Marker Spy Pen & Flashlight (Pack of 2) Protect property with invisible markings to help identify lost or stolen items like electronics, books, cameras, artwork, collectibles, etc. Kit includes (2) DNA Invisible Marking Pens and (2) UV Light Pens Permanent on most surfaces Won't deface property or affect resale value like engraving. Mark College texts to help prevent resale fraud.