"See enemy equipment, field upgrades, and killstreaks through walls, mark them for your team by aiming down sights. Hack enemy Claymores, Proximity Mines, C4, and Trophy Systems"
Engineer (previously called Spotter) highlights enemy equipment, Field Upgrades, and killstreaks in red that is visible through walls on the user's HUD, similar to the SitRep and Engineer perks from previous games with one addition: the user can highlight the equipment/Field Upgrade/killstreak for their teammates by aiming down sights on them. Since the 1.14.0 Perk rebalancing it allows the user to hack enemy Claymores, Proximity Mines, C4s and Trophy Systems which was previously part of the perk E.O.D.
Call of Duty: Modern Warfare II[]
"Spot enemy equipment, Field Upgrades, and Killstreaks through walls. Aiming down sights highlights them for the team. Hack enemy Claymores, Proximity Mines, C4, and Trophy Systems."
— In-game description
Spotter returns in Call of Duty: Modern Warfare II as a Bonus Perk and in Call of Duty: Warzone 2.0 as a Tier 1 Perk.