This Mossberg 590 Shockwave features a 3" chamber, a fixed CYL bore choke, an SB Tactical brace, and an Ergo grip. 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.