South Korea is installing new long-range thermal (heat imaging) sights at 53 front line positions along the 253 kilometers long North Korean border (the DeMilitarized Zone or DMZ). Details were not given but South Korean firms already build thermal sights for armored vehicles and rifles. These have ranges from one kilometer (for the rifle sight) to several kilometers, for the larger vehicle mounted sights. The new thermal sight for DMZ outposts is apparently more like the sight built for tanks, meaning that it can see to the other side of the four kilometer wide DMZ and have a clear view (at night, even with fog) of anyone crossing the middle of the DMZ. South Korean military commanders are particularly eager to avoid any more embarrassing situations where North Korean defectors simply walk across the DMZ at night with no one on the south side noticing.