Toggle on the UV LEDs to illuminate the security strip located on all bills $5 and up. A convenient guide on the front of the unit show you the color and location for each denomination. Toggle on the white LED to illuminate the platter. Look to the right, and see the watermark portrait appear. This should mirror the portrait in the center of the bill. (on the $5, the numeral 5 appears, not an image of Lincoln). For extra protection, use the Counterfeit Detector Pen, which is located in a slot on the right side of the machine.