C-4 (or Composition C-4) is a plastic explosive. By itself, C-4 is harmless. You could shoot it, set it on fire, etc and it won't go off. But as blasting cap is placed on it, all the user needs to do is press a detonator and it goes off. The CIA used it in the exploding cigar, and it's used by special forces groups worldwide.
Weapons with C-4 in themEdit