Pshine Invisible Ink Pen & Black Light Combo,4 Colors (Red, Blue, Yellow, Purple),pack of 20 Currency Checker. Invisible Ink Pen Requires 3 AG3 Button Cell Batteries (included) Smart Money Counterfeit Detector Pen with Reusable UV LED Light Security Marking Packaging include: 20pcs pens+1pcs headset bobbin winder (Note: The headset bobbin winder will be random shipments)