The SIG Sauer P228 is a military-grade adaptation of the earlier P226 pistol. It is semi-automatic and usually chambered for the standard nine-millimeter Parabellum ammunition. It is distinguished from its predecessors by a shorter barrel and a 13-round-capacity magazine.
Adopted by the U.S. military in 1991, the P228 is referred to as the M11. It has been equipped to Military Police units and several law enforcement agencies. In Europe, it has been used extensively by local police departments. The P228 has also proven to be a popular weapon in the civilian market. It benefits from a compact design and its use of a commonly available ammunition.