Modified 9mm ammunition.. Works in firearms chambered for regular 9mm ammo. A 9mmP (9mm para) slug is larger than that of the standard 9mm slug. Less propellant is used, but it is compensated by having a higher grain and the fact that 9mmP are used at short ranges. Most police SWAT, FBI HRT, and Special Ops teams use 9mmP because it has a higher stopping power, fragments more than a 9mm regular, and usually doesn't exit the body.

The "9mm para" is, in fact, the the 9mm Parabellum, otherwise known as the 9mm among those who aren't familiar with their cartridges (e.g., gangsta's, TV writers, most Americans). More recent 9mm ammunition is indeed less prone to over-penetration and expands more reliably, but is still much the same as the Parabellum of old.