The following perks are available.

Tier 1
Sleight of Hand: Fast Reloading.
Pro: Fast Weapons Change.
Recon: Explosive damage shows target on mini-map.
Pro: Bullet damage shows target on mini-map.
Blind Eye: Air Support and Sentries are undetectable.
Pro: Fast lock-on for rockets. Increased bullet damage to vehicles.
Extreme Conditioning: Increased sprint time.
Pro: Climbing speed increased.
Scavenger: Get ammo from dead enemies.
Pro: Get more ammo.

Tier 2
Quickdraw: Faster Aiming.
Pro: Faster recovery from using grenade/equipment.
Blast Shield: Increased explosive resistance.
Pro: Resistance to flashbangs and stuns.
Hardline: Killstreaks require one fewer kill.
Pro: Two assists count as kill towards killstreaks. Deathstreaks require one fewer death.
Assassin: Immunity to UAV, portable radar, thermal, and heartbeat.
Pro: Immunity to CUAV and EMP, no red crosshair or name over you.
Overkill: Carry two primary weapons.
Pro: Second primary can have two attachments.

Tier 3
Marksman: Identify targets at more distant range.
Pro: Hold your breath for longer when sniping.
Stalker: Increased movement speed while aiming down the sites.
Pro: Add delay to enemy claymores before exploding.
SitRep: Detect Enemy Explosive and Tac Insert.
Pro: Opposing team's footsteps make more noise.
Steady Aim: Increased accuracy while firing from hip.
Pro: Weapon ready more quickly after sprint.
Dead Silence: Quieter movement, recon does not work as well against you.
Pro: Do not take any fall damage.