The requirement for an easily portable, light AA gun, with more “punch” than mere rifle caliber machine guns, was made apparent to the British and other armies in the early war period. The British did have a license to build the Swiss Oerlikon 20mm, but the Oerlikon was a complex design and was costly in time, resources, and currency to build.

Displaced Polish designers who fled to the UK were able to adapt their designs and these evolved into the Polsten 20mm autocannon. A much simpler design, the Polsten used the same ammunition and drum magazine of the Oerlikon, as well as a simpler 30 round box magazine (represented on this model).

The Polsten was used extensively by Commonwealth forces, in field mounts of a single gun up to quad mounts, as well in vehicles, including trucks, the Centaur AA tank, the innovative Canadian Skink AA tank and on early models of the Centurion tank.