This Lewis Machine & Tool Defender 2000 features a piston system. It comes with one 30-round magazine and an EOTech 552 with original box (needs batteries). 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.