When accuracy and a truly level playing field matter, Anarchy Outdoors has created what we consider to be the perfect scope base. Not only is this sleek design compatible with all scope rings, but we've also incorporated a removable bubble level into the rail* to help improve accuracy.Specifications: 00 MOA 20 MOA 30 MOA 40 MOA Made in the USA* This rail is NOT compatible with the .300 WSM, 338 Lapua, or .300 PRC RPRs.