The Range-R manufacturers explain that the device is to be held against a wall. Users then push a couple of buttons that send radar pulses through the wall to detect if anyone is inside.
The device covers a conical view of 160 degrees and a range of 50 feet. The ‘Range-R, “will penetrate most common building wall, ceiling or floor types — including poured concrete, concrete block, brick, wood, stucco glass, adobe, dirt. It will not penetrate metal.”