The SIG SG 55X family of rifles was created in the late 1970s. Production began in the 1980s and continues today due to the popularity of the weapon platform. The 55X family of rifles fire the 5.56x45mm round and most fire in either semi or full-automatic. Various militaries, special forces, and law enforcement agencies around the world use this weapons platform; specifically the SIG 552 or 551 due to their compact size, firepower, reliability and their ability accessorize.
This SIG SG 551 is shown with a Leupold rifle sight.