This Davidson Firearms DD-15 features a carbine-length system, an adjustable arm brace blade, a 1/7 twist, and a muzzle brake. One 30-round magazine is included. 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.