This Aero Precision M5 features an Aero Precision M5 lower receiver, a Bear Creek Arsenal BC-10 right-side charging upper, a 20" black nitride straight fluted heavy barrel, a 15" M-Lok split rail with BCG and charging handle, a Rock River Arms two-stage match trigger kit, a Magpul PRS Gen 3 precision-adjustable stock, a UTG ACCU-SYNC spring-loaded AR15 flip-up sight set, and a Magpul MOE-K2 grip. One 20-round Hex 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.