Laser rangefinders for fire control applications and laser designators for semiactive guidance of precision projectiles demonstrated their utility in combat situations in Vietnam. The first laser rangefinder used a pulsed ruby laser; however, the low repetition rate limitation of the ruby laser precluded its use as a designator. A further disadvantage to ruby lasers is their visible radiation which, of course, is detectable by the eye. Ruby lasers were soon replaced by neodymium doped yttrium aluminum garnet, YAG:Nd+3, lasers which, because of their higher pulse repetition rate capability, could be used in designator applications as well as for rangefinders. Through continued research and development these devices eventually became sufficiently lightweight to not only become manportable designators, but also rangefinders which could be used in the same way as binoculars are employed. A number of rangefinders and designators are currently in production or about to be put into production. Approximately a decade ago, clisideration was given to the possibility of using CO2 lasers as rangefinders and designators. As with YAG:Nd -I devices, the work has initially been concentrated on rangefinders. These devices have advanced to the stage where three models one from Honeywell, one from Raytheon and one from Marconi have been delivered to the Army Night Vision and Electro-Optical Laboratory for evaluation. In addition, Hughes Aircraft Company will use a Marconi laser in a CO2 rangefinder for the XM-1 tank.