This is the AR-15 magazine .223 / 5.56 30 round with the "Muddy Girl" design, by Matrix Diversified Industry (MDI). It is a magpul pmag magazine that has been finished with a coloring technique known as water transfer printing (also known as hydrographic printing).
Note- the magazine is only contains graphics on the bottom of the magazine that is visible when it is fully inserted into the firearm