Technically, the MP5K is no more than a shortened MP5 (K stands for "Kurz", short in German) with vertical front grip. The MP5K-PDW (Personal Defense Weapon) is essentially an MP5K with a folding buttstock and threaded barrel. The three-lug barrel of the MP5K-PDW allows the attachment of suppresors, flash hider, blank firing device or grenade launcher.

The MP5K-PDW fires from a closed-bolt position using HK's unique roller-locked bolt system during all modes of fire, which helps to make the MP5K and MP5K-PDW submachine guns extremely accurate and controllable.

A selection of optional trigger groups allow for single fire only, full automatic, 2-round and 3-round burst options. The weapon's unique modular design and a variety of optional buttstocks, sight mounts and other accessories gives the MP5K-PDW extraordinary flexibility to meet any mission requirement. The MP5K-PDW can be conveniently carried by right or left handed individuals using a variety of specially designed carrying slings, shoulder and thigh holsters.

Designed for vehicle operators, aircrew members, security details, and others who require a small, but powerful weapon; it is comparable in performance to full size MP5s. The size and weight of the MP5K-PDW make this weapon the ideal choice where a rifle or full-sized submachine gun is unmanageable and a handgun is a poor compromise.