In 2002, American infantry finally got a portable thermal imager (displays a picture based on heat differences), like those used by American tanks in the 1991 Gulf War. The U.S. Army has two militarized devices (medium and heavy versions of the AN/PAS-13) for the infantry, weighing 5 and 5.5 pounds. The heavier device has about twice the detection range and is bulkier. Detection range for people is 1.5 and 2.8 kilometers. For vehicles, it is 4.2 and 6.9 kilometers. Magnification is 3.3X and 10X. Battery life is 3.5 and 7 hours. Batteries can be replaced or recharged. The smaller device is 15.8 inches long, the larger one is 18.1 inches. Both are 6.3 inches high and wide. Both can be mounted on weapons. Lighter devices are available for the civilian and police market. The 27 ounce "Thermoscope" is powered by four AA batteries (for 3-4 hours use) and looks like a snipers telescope, and can be mounted on a rifle, or used by itself. Look into the eyepiece, and you see a 320x240 pixel black and white image and detect people out to about 600 meters. People and animals show up clearly, although vehicles are more detailed around their engine compartments. It is almost impossible to hide your heat. These things even detect fresh foot prints. But these devices are expensive, the AN/PAS-13 costing up to $17,000 each.