Equipment in Modern Warfare 2 includes Lethal and Tactical. Lethals are deadly with the ability to toss them and plant some of the others. All Tactical equipment can be tossed and mainly used to confuse the enemy.
Lethal

Frag
Cookable frag grenades.
Unlocked: Default

Semtex
Timed sticky explosives.
Unlocked: Default

Throwing Knife
Throw it and pick it back up.
Unlocked: Default

Tactical Insertion
Choose where to respawn.
Unlocked: Level 11

Blast Shield
Increased explosive resistance.
Unlocked: Level 19

Claymore
Proximity activated explosive mine.
Unlocked: Level 31

C4
Remote detonation explosive.
Unlocked: Level 43
Tactical

Flash Grenade (x2)
Blinds and deafens target.
Unlocked: Default

Stun Grenade (x2)
Disorients and slows targets.
Unlocked: Default

Smoke Grenade
Smoke Screen.
Unlocked: Default