The Magpul PMAG is a standard factory replacement magazine for your Ruger AR-15 platform rifle. This magazine is designed to be compatible with AR-15 pattern rifles chambered in 5.56 NATO and contains 10 rounds of ammunition. The magazine is made by Magpul from from high quality materials and features a matte black finish. The most important aspect of this magazine is the fact that it is made by Magpul for Ruger so you can rest assured that the magazine will meet and exceed the specifications and tolerances set forth by the factory engineers. You can be all but certain that this magazine will fit perfectly and function flawlessly the same as with the magazine(s) that shipped with your firearm.