Rocket Launchers are what they are called. There aren't many uses for them, but they are mainly for taking down enemy helicopters and heavily armoured enemies.
The Russian RPG-7 still retains its traits in games. Point, click, ka-boom! It can be used to kill multiple enemies, or take out vehicles and Juggernaughts. At it's Base, it has extreme damage, very high accuracy, and extreme aggro.
The United States/German FIM-92 Stinger shares the same name in-game. It shares all of the RPG's traits, but with one special feature: it can lock on. This makes it an air-support only weapon, and should only be even held on the levels where there are helicopters. Rios uses this weapon to kill Dalton. At it's base, it has highly extreme damage, extreme accuracy, and highly extreme aggro.