A couple of years ago, one of the companies at Dayton, was giving away an RF detector. It was about 3/4 inches in diameter, about 1/2 inch thick, made of transparent plastic (light yellow, orange, or pinkish red), and had 9 or 10 small LEDs arranged in a circle. It was powered by a button battery. In the presents of RF (say from a hand held), the LEDs would turn on in a circular, chase pattern for about 5 seconds. I have searched for these several times, and even went so far as to e-mail several companies I found in the Thomas Registry site. All to no avail. If any one out there has ever seen one of these, or knows where they came from (company who gave them away), or who made them, I'd appreciate hearing from you.