Anti Air is a gear perk that boosts your weapon damage against flying vehicles. It helps you deal with FND helicopters and planes without relying on a launcher.
Your shots hit aircraft harder, so a rifle or machine gun can bring down a helicopter far faster than normal.
Wear one of the gear pieces that carry it: Rioter Gloves. Each piece only takes one body slot, so plan around the other perks you want.
Worth wearing when you are being chased by air units a lot. In stealth-heavy play you will rarely notice it.
Pair it with armor-piercing ammo and a heavy weapon for the fastest helicopter kills.