The SG 551 is the carbine variant of the SG 550, featuring a 16-inch barrel and folding stock for use by vehicle crews and special forces units. Type: Rifle Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 1987, Switzerland Weight: 112 oz Overall length: 35.4" Status: Active Military use: Yes Intended use: Military, Collecting