ShoppingClick for larger image 18" MARK 12 BARREL 5.56MM Sale Price: $169.00 Regular Price: $189.99 You Save: $20.99 Quantity: 18" Mark 12 Barrel 5.56 mm4140 Chrome MolyThreaded Barrel — Thread Pitch 1/2 x 28Gas Block Diameter .750Gas Tube Length — Rifle1-9 RH Barrel Twist6 Lands and GrovesButton Broached