Meet the radar-detector group’s brain-damaged member. Its seven-character display can’t show units of measure, so when the screen reads “30,” for example, you don’t know whether you’re going 30 miles per hour or there’s a camera 30 feet down the road. You’d have to memorize the owner’s manual to decode all the possible readouts. One redeeming feature: It knows which way the cameras point, which minimizes false positives. But its database seemed smaller than those of the other models tested.