The SA-203 is a weapon featured in Unit 13.
The SA-203 seems to resemble an M203 40mm grenade launcher generally attached to assault rifles or carbines as an underbarrel extension, however, Unit 13 doesn't cotton to such behaviour. This weapon is an M203 with an M16/ M4A1 collapsible butt attached to improve accuracy. Unlike its real-life variant, the game's version is extremely unfaithful; a grenade fired too close to oneself automatically kills the wielder. In fact, grenades fired from such a weapon will have a fuse that detonates it only when it has traveled a safe minimum distance.