It is a SIG 556 SWAT. 16" barrel with YHM flash hider. It has the vortex strikefire optic, troy forward grip, magpul rail ladders, original SIG panel covers, extra firing pin, buttpad extention, Sig hard case, sig magazine, cable lock. It has had 700 rounds through it. The only markings on it are from where the round cases hit it on the way out. Right where they would hit the deflector on a normal AR-15. And it is piston operated, has a adjustable folding stock, saw style pistol grip. $1,000.