Laser designator
From Halopedia, the Halo wiki
The Laser Designator is a United Nations Space Command piece of equipment.[1]
Description
The Laser Designator could most likely be used by a forward observer to mark out long range targets for air strikes or artillery bombardments.
The designator uses the same butt-stock, pistol grip and main section as the SRS-99D S2 AM Sniper Rifle, with the only difference being the absence of an ammunition magazine and barrel, and the replacement of these with a laser designator and different optical scope.[2] The UNSC Laser Designator also has a Misriah logo on its stock, a feature retained from its SRS99D-S2 AM roots.
It was first seen in use during the short video, Halo: Last One Standing, by an injured UNSC Marine Orbital Drop Shock Trooper, S. Hartley, during the Battle of Sector Six. Though injured, he used it to acquire the trajectory information of the John-117's descent through Earth's atmosphere, pinpointing his eventual crash site.
Target Locator
In Halo: Reach, there is a new weapon similar in function to the laser designator called the Target Locator, used to designate ground targets. This device is much smaller than the Laser Designator, and has a small view screen in it.[3] When the trigger is held down for several seconds, a blue circle appears on the ground and large blasts fall from the sky, doing a large amount of area damage.[4]