The feature works similar to other explosives, but it can only be used outdoors or when the enemy is in clear view of a window or open door. When equipped, a circle will appear on the ground that can be maneuvered to encircle one or more enemy NPCs. Anyone within the circle will be taken out by a headshot from a sniper.
The feature becomes available after first speaking with Robert Marshall in the mission Creature of Habit. Lincoln can carry a maximum of three markers, and despite them being listed under explosives, the IRA Bomber perk does not increase the amount. Additional support markers can be purchased from the Arms Dealer or found at the locations listed below.
- The service cannot be used to kill civilian NPCs.
- Despite being listed under equipment, Lincoln's carry capacity is not affected by the IRA Bomber perk.
- Unlike other items under the equipment menu, they are not picked up automatically. The player must use the interact button to add them to their inventory.