This Ruger AR-556 features a rifle-length M-Lok upper, a 1/8 twist, an Omni muzzle brake, and a no-name red/green dot. Purchase includes the original box, owner's manual, one 30-round magazine, an extra carbine upper with a 16" barrel with 1/8 twist, a CMMG .22 LR conversion kit with two 25-round magazines, and extra pins and springs. Get the best bang for your buck when you get a Certified Used Firearm. When you see the Certified Used stamp on any of our firearms, you can be confident that you're getting exactly what you want - a gun only in very good to excellent condition and held to the highest quality standard. All Certified Used Guns come with a 'no questions asked' return policy.