H-165 Forward Observer Module

The H-165 FOM or Target Locator is a United Nations Space Command artillery fire designator. The Target Locator is a compact, handheld laser emitter designed for acquiring and designating targets for small-scale artillery support. While similar in function to the UNSC Laser Designator, the Target Locator is much smaller and can be held with one hand. The Target Locator also has both 2x and 4x magnification.

The Target Locator appears as a weapon in Halo: Reach. When the trigger is held down for several seconds, a green laser beam marks the targets, and a red circle is projected on the ground around the target area. Once the target has been locked, 7 missiles strike the designated area from above, doing a large amount of area damage.

The Target Locator can also lock onto an individual target, with the projected circle following the target until the strike commences.

Trivia

 * Destroying two vehicles with a single fire mission from the Target Locator in the mission ONI: Sword Base unlocks the Achievement Two Corpses in One Grave. This is similar to the Halo 3 Achievement Two for One, which is unlocked by earning a Double Kill with the Spartan Laser, another anti-vehicular specific weapon.
 * The Target Locator is available only in Firefight and Campaign. It does not appear in Matchmaking or Forge for balancing reasons.
 * If infinite ammunition is enabled, the Target Locator will still deplete but, if it has zero shots remaining and the reticle has become a cross, one can continue to fire the Target Locator and HUD rings will appear on the ground as if a target had been designated. However, no rounds will impact the ground. Also, If bottomless clip is enabled, the Target Locator can still create HUD rings on the ground while it is reloading without any cooldown, though no rounds will impact the ground if another location is already designated.
 * Even when the Target Locator's fire missions are depleted, a player can still pick them up. After every round in Firefight, if the player still holds the Target Locator, its will regenerate back to the firing capacity of 2 shots.
 * The fire mission is composed of seven missiles, another reference to Bungie's frequent usage of their favorite number, seven.
 * Upon acquiring a target lock with the Locator, a radio message will often be recieved by the player from the artillery crew such as "target acquired" or "fire for effect".
 * After a certain period of time(usually several minutes), an additional shot will be added to the locator. This is most noticeable in the level, ONI: Sword Base.

List of appearances

 * Halo: Reach