Air pistols encompass all sporting devices that fire projectiles using cold gases (usually compressed air, occasionally CO2). For competitive use, air pistols are permitted with a maximum muzzle energy of 7.5 joules and a caliber of 4.5mm. Compressed air is introduced into the weapon's system from a pressure container, where it is compressed using a pump or filled from a compressed air bottle, and is briefly released through a valve activated by the trigger, propelling the projectile through the barrel.
Modern air pistols come in four different designs: with a side cocking lever, with a compressed air or CO2 cartridge, or as self-compressors, with current competition air pistols (often referred to as match air pistols) using only compressed air as a propellant.
The HW 45 air pistol from the German firearms manufacturer Weihrauch is among the strongest sport air pistols currently available in Germany. The design of the pistol is modeled after one of the most famous service pistols in the world. It has a very compact size for an air pistol with such high performance, and the grip panels are suitable for both right- and left-handed users.