This versatile pen wireless signal detector is a perfect kit to help you stay away from intention spying, no matter where you in a hotel, dressing room or anywhere personal privacy need to be secured. It utilizes the 4th generation RF broad-brand wireless detecting technology, it is a combination of RF and UV detection device, which allows you to detect wireless signals(brand between 100M-3000MHz), it is a very effective device to protect you from spying devices which required wireless signals transitions…It also could be used as a bill-tester, push the button on the side of the pen to illuminate the UV light to check for fake currency by detecting the water mark.