By using a flying beam of x-rays this company can quite literally see through walls! The technique is very much like how the picture on your TV is produced. A narrow beam of x-rays are projected to the target (like an electron gun in your TV) and the energy that is reflected back is recorded from exactly where the beam intersected the target (like how the phosphor glows in the picture tube when the electrons hit it). This builds up a picture of what is in side of the object being scanned. Items with low atomic numbers (such as explosives, drugs, cigarettes, and people) are shown in stark contrast to their surroundings.