The Heckler & Koch Universal Self-loading Pistol (USP) entered into production in 1993. It had a high sales success rate which contributed to its ongoing production and the development of several variants. It is in service within several law enforcement agencies and armed forces, e.g. in Germany, Greece, Spain and the US.
Variants of the HK USP 9 mm model: - the USP Compact which is shorter (173 mm length) - the HK USP Tactical variant which is longer (218 mm length) and uses .45 ACP