The C4 Explosive is one of two types of explosives in Apocalypse Rising, the other being the two types of mines. They are found at any military spawn, and can only be detonated using the C4 Detonator. They can demolish many buildings, including the Mansion. There are a lot of creative ways of using C4. Baiting is the key to reach such creativity, such as hiding it in a or underneath a vehicle, on top of a tower, near a storage crate, full of "precious" supplies as a trap, or even near the entrances of large buildings (i.e. hospitals, industrial buildings, etc.)
C4's, when activated, have a delay of around 3 seconds prior to explosion.