This Aero Precision M4 Carbine includes one 30-round magazine, a Magpul buttstock, an Aero Precision lower receiver, a Daniel Defense upper receiver, a Geissele cold hammer-forged barrel, a Geissele trigger, a BCM 13" handguard, and a permanently attached SureFire muzzle device. 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.