Tactical Mask renders the player immune to the effects of Nova Gas.
Its Pro version reduces the effects of Flashbangs and Concussion Grenades on the player by 90%. This is to say that if hit by a Flashbang, the player's vision will dim for a second before returning to normal. If hit by a Concussion Grenade, the player's vision will blur as if stunned, and movement and turning speed will be momentarily affected. This lasts for about two seconds before the player's vision returned to normal. It also reveals the general direction of any enemies that are hit with the player's Flashbangs or Concussion Grenades via a small yellow directional indicator near the cross-hair. If multiple enemies are stunned or blinded by the player's tactical grenades, multiple arrows will show up on his cross-hair. Ghost Pro users will not give off an indicator.
Tactical Mask returns in Call of Duty: Black Ops II. It reduces the effects of flashbangs, concussion grenades and shock charges. Like in the original Black Ops, the duration of the debilitating effect of concussion and flashbang grenades is reduced by 90%. The stun effect of shock charges is negated entirely. This perk, along with Flak Jacket, is very useful in objective gamemodes, as the objectives are bound to be bombarded with equipment from all angles.