November12, 2006: The U.S. Army is buying 7,500 Thermal Weapon Sights II (TWS II). These are weapons sights that detect differences in heat. This allows the shooter to see targets at night, or through sand storms, snow and mist day or night. There are three versions of TWS II, with 23 percent being the Light Thermal Weapon Sights (LTWS, for assault rifles and AT-4 anti-tank rifles), 52 percent are Medium Thermal Weapon Sights (MTWS, for 5.56mm and 7.62mm machine-gun) and 25 percent are Heavy Thermal Weapon Sights (HTWS, for heavy weapons like the .50 caliber machine-gun, and sniper rifles.) The LTWS has a battery that lasts 25 hours, those for the other two last 18.) The two larger sites have 3x zoom. On average, each sight costs, on average, about $10,000. This new generation of thermal sights are lighter and more reliable.