After trying, and trying, and trying I found that the product does not work as claimed. After following the instructions, and watching the "how to" video at the website, the LED detectors went from red to green, but the clipper was still on the quick (of a white nail). The product does not perform as advertised. Unforutantely, Amazone doesn't offer returns on 3rd party sellers, and the seller doesn't issue refunds since the manufacturer doesn't offer a guarantee that the product works. Don't waste your money. The concept is good, but the product sux.