This is the recoil reducing, adjustable length, AR style stock. Practically brand new. I've fired a few boxes of birdshot and about a dozen shells of 00 buck and a box of slugs with it. It works very well and looks totally badass but I prefer a more traditonal style stock. I had it on a Mossberg 590A1 so I know it'll fit all 500, 590 (not 590DA), 835, and Maveric 88. Comes with the big hex key but no packaging or forend. Here are some pics from the net. You too can look like this guy.