The second generation of AN/PAS-13 weapons-mounted thermal sights -- TWS II for short -- have undergone a weight-loss plan that includes smaller batteries. Input from solders in Iraq and Afghanistan was also incorporated into the latest upgrades. 

The AN/PAS-13 family will still have three different models for light, medium, and heavy weapons, with operational ranges of around 550 meters, 1,100 meters, and 2,200 meters respectively. The light sight will be used on the M16/M4 assault rifles, medium sight onto the M249 and M240 machine guns, and the heavy sight going onto the M2 .50 caliber machine gun, Mk-19 40 mm automatic grenade launcher, and M107 .50 caliber long-range sniper rifle.

One of the greatest advantages of the TWS II has been a redesign so that standard AA batteries could be used in all three versions. The first generation medium and heavy models used a heavier military-specific battery, but soldiers wanted AA batteries across the board. More importantly, the TWS II now uses fewer batteries. The TWS I light version used eight AA batteries, while its TWS II counterpart only users four AAs. 

Weight for the TWS II sights is down as well. The current light model with batteries weighs 2.7 pounds, the new model comes in at 1.9 pounds. The medium model currently weighs 5 pounds, while the TWS II version will weigh in at 2.8 pounds. The heavy version will drop from 5.3 pounds to 3.8 pounds. 

In September, a limited user test is to be used as an operational test to insure everything works well with general fielding starting in November 2005 if everything goes well. Two contractors will produce the sights. Up to 30,000 systems could be purchased over four or five years. Doug Mohney